Computer for Pharmacy Revised1.docx

**Computer in Pharmacy** 1. **Introduction** Today - - - - - Tomorrow - - - - - - - - - - - - **What are Computers?** ======================= Computers are machines that perform tasks or calculations according to a set of instructions, or programs. The f...

**Computer in Pharmacy** 1. **Introduction** Today - - - - - Tomorrow - - - - - - - - - - - - **What are Computers?** ======================= Computers are machines that perform tasks or calculations according to a set of instructions, or programs. The first fully electronic computers, introduced in the 1940s, were huge machines that required teams of people to operate. Compared to those early machines, today\'s computers are amazing. Not only are they thousands of times faster, they can fit on your desk, in your lap, or even in your pocket. ENIAC (Electronic Numerical Integrator and Computer) was developed by Dr. John W. Mauchly and J. Presper Eckert, Jr. in 1946 and was the first general-purpose electronic computer. It was built for the United States military to calculate the paths of artillery shells. Physically, ENIAC was enormous, weighing more than 27,000 kg and filling a large room. To process data, ENIAC used about 18,000 vacuum tubes, each the size of a small light bulb \-- took up a 30 x 50 feet space. The tubes burned out easily and had to be constantly replaced. **Commercially Available:** In 1951, the first commercial computer became available; it was called the UNIVersal Automatic Computer (UNIVAC 1) by Remington Rand. In 1953, the IBM 650 became the first widely-used computer. The company planned on producing only 50 units, but ended up making 1,000 of them. The development of this computer was enhanced by the invention of a core memory module that provided more memory size than the old vacuum tube method. **Microcomputer Development:** Dr. Ted Hoff at the Intel Corporation developed a microprocessor in 1971. This new technology allowed computers to run faster and shrink in size. By 1975, the first microcomputer, the Altair, was put on the market. It had no keyboard, no monitor, no hard drive, and no software for the cost of \$400. By 1976, Steve Jobs and Steve Wozniak developed the first Apple computer that was widely adopted by schools. **Storage:** In 1980, Alan Shugart invented the Winchester disk drive that could hold 30 megabytes of data. This created the custom of putting hard drives inside the computer. IBM took advantage of this development and became the PC of choice in the business world by 1981. **Processors:** The Intel 486, appeared by 1989, as the world\'s first one-million transistor microprocessor. It ran four times as fast as the 80386 chip and could process fifteen million instructions per second. By 1993, the Pentium processor hit the computer scene with 3.1 million transistors and 112 million instructions per second. Computers are good at storing and manipulating large amounts of information. They are also very accurate calculators and are thus able to carry out complex statistical analysis. Computers work through an interaction of hardware and software. Hardware refers to the parts of a computer that you can see and touch, including the case and everything inside it. **Homework:** Read the article available at http://plato.stanford.edu/entries/computing-history/ **Components of the Computer** A computer unit can be subdivided into (i) hardware and (ii) software. **Hardware:** refer to those components of the computer that can be seen, touched or carried about. It includes things like the computer central processing unit (CPU), monitor, hard disk, printer, keyboard, mouse, etc. **Mother** **Board** - core components **Processor** - brain of the computer which executes instructions and controls its operation #### **Random Access Memory (RAM):** working memory of the computer is called RAM. RAM can be accessed almost instantly, but all the information held in the RAM is lost when the computer is switched off. The higher the RAM size (\> 64MB) the better. #### **Central Processing Unit (CPU):** The CPU processes any information entered into the computer. #### **Cache:** This is an area of the computer memory used to store recently used data that can be retrieved again very quickly if needed. Modern computers are usually available with 512 kilobyte (Kb) cache memory. **Computer Devices** There are usually three kinds: input devices, output devices, and storage devices **Input device:** This converts incoming data and instructions into a pattern of electrical signals in binary code that are comprehensible to a digital computer. At one time punched-card and paper-tape readers were extensively used for inputting, but these have now been supplanted by more efficient devices. Input devices include typewriter-like keyboards; handheld devices such as the mouse, trackball, joystick, trackpad, and special pen with pressure-sensitive pad; microphones, webcams, digital cameras and optical laser scanner (e.g., scanners used with point-of-sale terminals in retail stores) that can read bar-coded data or optical character fonts as well as sensors that provide information about their environment---temperature, pressure. **Output device:** This reverses the computer input process, translating the digitized signals into a form intelligible to the user. Output equipment includes video display terminals, ink-jet and laser printers, loudspeakers, headphones, and devices such as flow valves that control machinery, often in response to computer processing of sensor input data. Some devices, such as video display terminals and USB hubs, may provide both input and output. Other examples are devices that enable the transmission and reception of data between computers---e.g., modems and network interfaces. #### #### **Printers:** include (i) dot matrix, (ii) ink or desk -jet and (iii) laser printers (color or black/white). The dot matrix printers do not produce high quality print-outs of documents but are cheap to use because the ribbons are usually very cheap. Desk-jet printers are good quality printers. They are often cheaper than laser jet printers #### **Storage Devices:** include hard disk, compact disks (CDs), DVD and flash drives used to store programs and information. Earlier ones used includes floppy disks (diskettes), optical disks, and zip tapes. The storage capacity of a storage device is often expressed in bytes. A byte is a unit of memory size. It is the unit most computers use to represent a character such as a letter, number, or typographic symbol (for #### example, \"g\", \"5\", or \"?\"). #### 1 kilobyte (kb) = 1000 bytes (1 kb) #### 1 megabyte (Mb) = million bytes (1000 kb) #### 1 gegabytes (Gb) = 1000 million bytes #### 1 terabytes (Tb) = 1000 Gb Most auxiliary storage devices---as, for example, CD-ROM and DVD drives, flash memory drives, and external disk drives also double as input/output devices. Even devices such as [smartphones](https://www.britannica.com/technology/smartphone), tablet computers, and wearable devices like fitness trackers and [smartwatches](https://www.britannica.com/technology/smartwatch) can be considered as peripherals, albeit ones that can function independently. #### Most new computers now have hard disks in terabytes space. While the most floppy disks could only hold about 1.45 -120 Mb of data (each), a CD can hold up to 650 Mb of data and DVD more than 1.5 GB. #### **Monitor:** displays the information entered or stored in the computer. A low radiation super video graphic array (SVGA) colour monitor puts less strain on the eyes when the computer is being used than an ordinary VGA monitor. The video card is an important component of the computer; it collects digital signals from the processor and drives the screen. **Types of Computers** While virtually every early computer was a large, monolithic machine capable of performing only simple equations, today\'s computing market features a range of advanced computer types, each with different key functions. **Desktops:** Desktops were once the most purchased computer type but lost that title to laptops in 2005. Desktops feature a relatively large central machine that requires a mouse, keyboard and monitor to function properly. **Laptops:** The new favorite among consumers, laptops do not require additional attachments. They have all necessary components built into the computer itself for maximum portability. **Netbooks:** Much like a smaller-sized laptop, these machines are designed to be portable for easy connectivity to WiFi networks. Netbooks typically have low onboard storage, limiting their usage for offline tasks. **Handheld computers**, also called personal digital assistants (PDAs), are battery-powered computers small enough to carry almost anywhere. Although not as powerful as desktops or laptops, handhelds are useful for scheduling appointments, storing addresses and phone numbers, and playing games. Some have more advanced capabilities, such as making telephone calls or accessing the Internet. Instead of keyboards, handhelds have touch screens that you use with your finger or a stylus (a pen-shaped pointing tool). **Tablet PCs** are mobile PCs that combine features of laptops and handhelds. Like laptops, they have built-in screens. Like handhelds, they allow you to write notes or draw pictures on the screen, usually with a tablet pen instead of a stylus. They can also convert your handwriting into typed text. Some Tablet PCs are "convertibles" with a screen that swivels and unfolds to reveal a keyboard underneath. **Palmtop Computers:** Similar to PDA systems, these handheld computers provide minimal functionality for scheduling events, checking emails and other basic computer tasks. **Buying a Computer** 1. Gather the local newspaper adverts! Or, do some price hunting on the Internet, on the websites for Walmart, Circuit City, Best Buy, Office Depot, Target or any other retailer. This will give you a picture of what is currently available. Pay careful attention because your ideas may be outdated. Markets and new technology emerge daily. 2. Maximize the computer\'s memory; try for at least 1GB RAM (or more). RAM (Random Access Memory) is the black \"memory stick\" (silicone chip) inside of the computer that helps it to run quicker. It lessens those blank screens that often appear when switching in between programs. It is good to have as much as you can. If you can get more than 1 GB, please do so. You can add memory easier at a later time, if you choose. 3. Hard Drive (HD) space is often confused with \"memory.\" All of your programs are stored in HD, including your Operating System, which is Windows Vista (or XP), in most cases. You will want to maximize this as well. Photos, videos, games and software take up the most room. Think of your future needs. You will have the computer for awhile. Your family\'s items will be stored on the PC, as well. Go for at least 100GB or more of HD space. GB is short for Gigabytes. 4. Buy a brand of computer that does not need a lot of repair. **HP/Compaq,** Dell, Toshiba and Acer are better. 5. Laptops can require different specifications, including those listed below. - - - - - - - - - - - - - **Note that computers** - - - - - - - - - **SOFTWARE** - - - - - Software can be: **Software types** - - - a. - - - - - - - - - - - - - - - - - - - - - - - - - - +-------------+-------------+-------------+-------------+-------------+ | **OS Name** | **Computer | **Target | **Security | **Best | | | Architectur | System | Threat** | For** | | | e | Default** | | | | | Supported** | | | | +-------------+-------------+-------------+-------------+-------------+ | **Windows** | X86, | Workstation | Huge | Apps, | | | x86-64, | , | | Gaming, | | | | Personal | | Browsing | | | | Computer | | | +-------------+-------------+-------------+-------------+-------------+ | **Mac OS** | 68k, Power | Workstation | Negligible | Apple | | | PC | , | | Exclusive | | | | Personal | | Apps | | | | Computer | | | +-------------+-------------+-------------+-------------+-------------+ | **Ubuntu** | X86, | Desktop/ser | Negligible | Open Source | | | X86-64, | ver | | Downloading | | | Power PC, | | | , | | | SPARC,\ | | | Application | | | Alpha. | | | s | +-------------+-------------+-------------+-------------+-------------+ | **Fedora** | X86, | Desktop/ser | Negligible | Coding, | | | X86-64,\ | ver | | Corporate | | | Power PC, | | | Use | | | SPARC,\ | | | | | | Alpha. | | | | +-------------+-------------+-------------+-------------+-------------+ | **FreeBSD** | X86, | Server, | Negligible | Networking | | | X86-64, PC | Workstation | | | | **(**free | 98, SPARC, | , | | | | UNIX based | others. | NAS, | | | | open-source | | embedded | | | | software) | | | | | +-------------+-------------+-------------+-------------+-------------+ *Other OS includes* - ### *Solaris - Best for Large workload processing, managing multiple databases, etc. Solaris is a UNIX based operating system which was originally developed by Sun Microsystems in the mid-'90s. In 2010 it was renamed as Oracle Solaris after Oracle acquired Sun Microsystems. It is known for its scalability and several other features that made it possible such as Dtrace, ZFS and Time Slider.* - ### *Chrome OS is another Linux-kernel based operating software that is designed by Google. As it is derived from the free chromium OS, it uses the Google Chrome web browser as its principal user interface. This OS primarily supports web applications.* - *CentOS is another community-driven open source free software that allows robust platform management. It is best for developers who are looking for an operating system that simply helps them to perform their coding tasks.* - *Debian is again a Linux kernel-based free open-source OS. It comes with over 59000 packages and is a pre-compiled software bundled in a nice format. It is easy to install and offers a user-friendly interface.* - *Deepin is an open-source operating system based on Debian's stable branch. It features DDE, (Deepin Desktop Environment built on QT. It has been praised for its beautiful aesthetics and very appealing interface* b. ***Programming software*** - - - - - - - - - - c. ***Application software*** - - - - - - - - - ###### Presentation - e.g., Power point, Harvard graphics. - - - - - ***Application software can be OPEN or CLOSED (proprietary or commercial) source*** a. ***Open source software*** - - - --------------------------------------------------------- --------------------------------------------------------------------------- ***Open source*** ***Commercial*** *Install and use freely* *Pay to install and use* *Vulnerable to malicious users* *More secure* *Might not be as user-friendly as commercial versions* *Often user friendly* *Authors make source codes available (can be modified)* *Authors do not make source codes available (cannot be modified)* *Eg,Apache web server, Moxilla Firefox browser* *Eg, MS Excel, MS Word, SPSS (statistical package for social scientists)* --------------------------------------------------------- --------------------------------------------------------------------------- - - - - - - - - - - - - - - -------------------------------------------- ---------------------------------------------------------------------------------------------------- ***System software*** ***Application software*** *No user interface* *There is user interface* *User cannot see the system software* *User can see the application software using a graphical user interface* *User cannot work in system software* *User can work in application software* *User cannot create user-written software* *User has an option to create his user-written software and use the software for its personal use* -------------------------------------------- ---------------------------------------------------------------------------------------------------- **WORD PROCESSING SOFTWARE** - - - Examples - - - - - - - Features - - - - - - - - - - - - - - - - - - - Uses  - - - - - - SPREADSHEET - - - MS Excel Spreadsheet Features of Microsoft Excel - - - - - - - - Benefits of MS Excel - - - - - - Tips for MS Excel - - - - - - - - - **Microsoft PowerPoint** - - - Features - - - - - Uses - - - - **Microsoft Access** - - - - - - - **Statistical Programs** - - - - - ### **Software Options** The software market is highly competitive and packages are becoming cheaper. They are also becoming more powerful, and upgraded versions appear regularly. Upgrades may mean that the software packages require upgraded hardware resources (such as hard disk space, microprocessor speed, and memory) to run effectively. Many software can be downloaded freely from the Internet. Computer magazines are a valuable source of comparison of articles on software and hardware. "Aftermarket" software books are often easier to use than the manual provided by software companies. The three broad categories of computer software useful in pharmacy are (1) general purpose programs, (2) special-purpose programs and (3) utility programs. **General-Purpose Software:** General-purpose software programs (such as word processing, desktop publishing, spreadsheets, and commercial database programs) perform routine daily activities or periodic analyses. The most important factor in choosing general-purpose software is access to local support. Some questions to consider are: Which package is the most common locally? Is local training available? What software is in use in other local offices with which the program interacts? ***Word Processing:*** Word-processing programs are replacing the typewriter. For most offices, up to 80 percent of computing time is spent on word processing. Word processors check spellings, search-and-replace functions, and generates tables of contents and make documents easier to produce. ***Desktop Publishing***. This software has word-processor features but is more powerful in handling graphics, large documents, and production of camera-ready copy to be used by a printer for newsletters, bulletins, training materials, or even books. ***Software suite: S***oftware "suites" usually contain a package of many software applications. Common software combinations in a software suite include word-processor, spreadsheet, database, graphics, and communication programs. For example, Microsoft Office is a software suite consisting of MS Word, MS Excel, MS PowerPoint and MS Access. These individual programs are combined in one software package and are designed to allow easy exchange or information among the different programs. In some cases, however, the package programs are not as powerful as individual stand-alone software. **Special Purpose Software:** Drug management systems often need special-purpose commercial software packages, such as presentation graphics, project management, statistics, accounting, bibliographic, and communications programs. **Computerised health information management systems**: Routine administration systems useful in pharmacy include Patient Administration Systems (e.g., Chemtec Alchemist 3000 for pharmacy labeling/patient medication record with prescribing and dispensing error alerts), Clinical Information Systems, and Hospital Information Support Systems. A system for unifying all fragmented structures that exist in all aspects of health care today is a comprehensive medical/pharmaceutical information system developed to offer a wide area network of information. An example is HealthPlus^®^ software allowing linkage of all hospitals, community practitioners, clinics, community and hospital pharmacies and laboratories, and nursing homes thus allowing comprehensive capture and storage of patient information. ***Presentation Graphics***. Presentation graphics packages can be useful for preparing effective and attractive graphical reports, overhead transparencies, and slides. ***Project Management.*** Project management software organizes and tracks project task to be accomplished according to a defined schedule and shows potential conflicts in the use of resources. Budgeting information can also be included. ***Statistical packages***. Although spreadsheets and databases have simple statistical functions, it is sometimes preferable to use a dedicated statistical packages. **Epi Info**, is an example. Developed and distributed by the WHO and the Centre for Disease Control and Prevention in USA (CDC), it integrates database and statistical functions simplifying epidemiological studies. ***Accounting***. Accounting programs are available with a wide range of capabilities. Basic bookkeeping can be done with spreadsheets, but a dedicated accounting package is often more appropriate. Selection depends on local factors. ***Bibliographic.*** Bibliographic software greatly facilitates storing, searching for, retrieving, and manipulating bibliographic information on books, journals, training materials, and government and project documents. This kind of software requires staff to keep the database up-to-date. ***Communications***. Communications software, initially designed to send and receive files via fax or modem, is evolving rapidly to electronic mail and access to on-line services. Example include SuperVoice for telephone and fax communication via the computer, Outlook Express and Pegasus for e-mail communication. **Utility Programs.** Utility programs help manage and maintain computers and stored data. Common utilities include antivirus (eg Norton antivirus), file management program, file backup, file exchange, data recovery and data compression. A current antivirus program is absolutely vital for computer units that handle essential day-to-day functions such as inventory control, drug registration, accounting, or maintenance of national health statistics. It is also essential for any system that receives data from outside sources, including branch offices within the country. **Custom Software**: Development of custom-built software, such as an inventory program, is a complex and time-consuming task. Although the idea of custom-built software is attractive, purchasing software that has already been written and tested by others is usually preferably, unless a suitable program cannot be found. If new software does need to be developed, it is important to approach this task in a step-by-step fashion. ***What are files and folders?*** --------------------------------- **Files and Documents:** - - - - - **Folders:** - - ***Moving information between files*** -------------------------------------- Most programs allow you to share text and images between them. For example, you can copy text or a picture from a webpage in Internet Explorer to a document in WordPad. When you copy information, it goes into a **temporary storage area called the Clipboard**. From there, you can paste it into a document. Electronic Databases **Definition** - - - -  **Database Table** - - - - - - - - - - - - - - - - - **Types of databases** - - - - - - - - - - - - - - - - - - - - 1. - 2. - 3. ***The relational model*** -------------------------- - - **Structured Query Language (SQL)** - **Evolution of the database** - - - - - - - - **Database management system (DBMS)** - - - **Common database challenges** - - - - - - **Computer Network** A computer network is any set of computers or devices connected to each other with the ability to exchange data. When we refer to Computer Networking (or Data communications or Datacom), we mean the communication between computer systems or devices. All networks are interconnected to allow communication with a variety of different kinds of media, including twisted-pair copper wire cable, [coaxial cable](about:blank), [optical fiber](about:blank), [power lines](about:blank) and various wireless technologies. The devices can be separated by a few meters (e.g. via Bluetooth) or nearly unlimited distances (e.g. via the interconnections of the Internet). The three types of networks are (1) **Internet**, (2) **Intranet**, and (3) **Extranet**. Different methods are used for networking. Examples are: - - - - These days, networking is frequently achieved using CABLING or RADIO/MICROWAVE communication. A wireless network is basically the same as a LAN or a WAN but there are no wires between hosts and servers. The data is transferred over sets of **radio transceivers**. These types of networks are beneficial when it is too costly or inconvenient to run the necessary cables. Network users can share printers and some servers form a workgroup, which usually means they are in the same geographic location and are on the same LAN. Network administration can see networks from both **physical** and **logical perspectives**. - - For example, a common practice in a campus of buildings is to make a set of LAN cables in each building appear to be a common subnet, using [virtual LAN (VLAN)](about:blank) technology. **The Internet** It is a global system of interconnected computer networks that use the standard Internet Protocol Suite (TCP/IP) to serve billions of users worldwide. It is a ***network of networks* that consists of millions of private, public, academic, business, and government networks of local to global scope** that are linked by a broad array of electronic and optical networking technologies. Unofficially, the **Internet** is the set of users, enterprises, and content providers that are interconnected by **[Internet Service Providers](about:blank) (ISP)**. It **carries a vast array of information resources and services**, most notably the inter-linked hypertext documents of the World Wide Web (WWW) and the infrastructure to support electronic mail. The Internet offers electronic communication in various dimensions including emailing, telephoning, social networking (Facebook, Twitter, etc). It has greatly facilitated personalized marketing which allows a company to market a product to a specific person or a specific group of people more so than any other advertising medium. Examples of personalized marketing include online communities such as MySpace, Friendster, Facebook, Twitter, Orkut and others which thousands of Internet users join to advertise themselves and make friends online. From an engineering viewpoint, the [Internet](about:blank) is the set of subnets, and aggregates of subnets, which share the registered [**IP address**](about:blank) space and exchange information about the reachability of those IP addresses using the [Border](about:blank) [**Gateway**](about:blank) [Protocol](about:blank). Typically, the [human-readable](about:blank) names of servers are translated to IP addresses, transparently to users, via the directory function of the **[Domain Name System](about:blank) (DNS)**. Over the Internet, there can be [business-to-business (B2B)](about:blank), [business-to-consumer (B2C)](about:blank) and [consumer-to-consumer (C2C)](about:blank) communications. Especially when money or sensitive information is exchanged, the communications are apt to be secured by some form of [communications security](about:blank) mechanism. Intranets and extranets can be securely superimposed onto the Internet, without any access by general Internet users, using secure [Virtual Private Network](about:blank) (VPN) technology. **Network topology** This is the way in which computers, printers, and other devices are connected, physically and logically. A network topology describes the layout of the wire and devices as well as the paths used by data transmissions. The common topologies used in computer network, often considered basic topologies include, Bus, Star, Tree (hierarchical), Linear, Ring, and Mesh (partially connected or fully connected).    Bus topology Mesh topology Ring topology Star topology Tree topology **Network Protocols** A **network protocol** defines rules and conventions for communication between network devices. It includes mechanisms for devices to identify and make connections with each other, as well as formatting rules that specify how data is packaged into messages sent and received. Protocols for computer networking all generally use [packet switching](http://compnetworking.about.com/od/networkprotocols/f/packet-switch.htm) techniques to send and receive messages in the form of *packets*. Some protocols also support message acknowledgement and data compression designed for reliable and/or high-performance network communication. Hundreds of different computer network protocols have been developed; each designed for specific purposes and environments. **Internet Protocols** The Internet Protocols provide computers the basic ability of transferring data from one computer to another. Besides [IP](http://compnetworking.about.com/od/networkprotocolsip/g/ip_protocol.htm) itself, there are two levels of protocols that integrate (co-exist) with IP to provide additional capabilities. These are - - The higher level protocols interact more closely with applications like web browsers while lower-level protocols interact with network adapters and other computer hardware. TCP and [IP](http://compnetworking.about.com/library/glossary/bldef-ip.htm) are two distinct network protocols, technically but so commonly used together, however, that **TCP/IP** has become standard terminology to refer to either or both of the protocols. IP corresponds to the Network layer (Layer 3) in the Open Systems Interconnection ([OSI) model](http://compnetworking.about.com/library/glossary/bldef-osi.htm), whereas TCP corresponds to the Transport layer (Layer 4) in OSI. In other words, the term TCP/IP refers to network communications where the TCP transport is used to deliver data across IP networks. The average person on the Internet works in a predominately TCP/IP environment. The Internet and most home networks support TCP/IP as the \"language\" computers use to find and connect with each other. Web browsers, for example, use TCP/IP to communicate with Web servers. IP addresses are the fundamental method for computers to identify themselves on the Internet and many other computer networks. It is a logical address which is a numerical label that is assigned to any device participating in a [computer network](about:blank) that uses the IP for communication between its nodes. IP addresses consist of four numbers separated by periods (also called a \'dotted-quad\') and look something like 127.0.0.1. An IP address serves two principal functions; host or network interface [identification](about:blank) and location [addressing](about:blank). It is used to [route](about:blank) data [packets](about:blank) between networks; IP addresses specify the locations of the source and destination nodes in the [topology](about:blank) of the routing system. For this purpose, some of the bits in an IP address are used to designate a [subnet work](about:blank). The number of these bits is indicated in [CIDR notation](about:blank), appended to the IP address; e.g., *208.77.188.166/24*. Although IP addresses are stored as [binary numbers](about:blank), they are usually displayed in [human-readable](about:blank) notations, such as 208.77.188.166 (for [IPv4](about:blank)), and 2001:db8:0:1234:0:567:1:1 (for [IPv6](about:blank)). Home computers and many other devices acquire IP addresses to join Internet Protocol networks. Since these numbers are usually assigned to internet service providers within region-based blocks, an IP address can often be used to identify the region or country from which a computer is connecting to the Internet. In order to avoid address conflicts, IP addresses are publicly registered with the Network Information Centre (NIC). These registered IPs are known as PUBLIC IPs are controlled by the Internet Service Provider (ISP). Computers on private TCP/IP LANs however do not need public addresses, since they do not need to be accessed by the public. For this reason, the NIC has reserved certain addresses that will never be registered publicly. These are known as PRIVATE IP addresses, and are found in the following ranges: Both public and private IPs can be assigned either as STATIC (physically type into the appropriate space in the computer) or DYNAMIC (automatically assigned) IPs. Although the public IP addresses you use for Internet access are controlled by ISPs, some Internet services assign you [static IP addresses](http://compnetworking.about.com/od/workingwithipaddresses/qt/staticipaddress.htm). Sometimes, it might be necessary to change or renew an IP (whether static or dynamic) address for a computer to work properly. For Internet service, you will need to contact the ISP to change any static IP address. However, most Internet services, use dynamic IP addresses via Dynamic Host Configuration Protocol ([DHCP](http://compnetworking.about.com/cs/protocolsdhcp/g/bldef_dhcp.htm)) (see below). The policies of ISPs dictate how to change these. If your computer is directly connected to the Internet, you can attempt to RELEASE and RENEW the address using "**[ipconfig](http://compnetworking.about.com/od/workingwithipaddresses/a/ipconfig.htm)" command** or a similar utility. When two or more computers are assigned the same IP address, there is usually IP conflict and the computers will not be able to communicate properly on the network. If using static addressing, you can directly set a new IP address on the device. If using dynamic addresses supplied via a [network](http://compnetworking.about.com/cs/routers/g/bldef_router.htm) [**ROUTER**](http://compnetworking.about.com/cs/routers/g/bldef_router.htm) (an electronic device that interconnects two or more computer networks, and selectively interchanges packets of data between them), you have a few options: - - - **Why Change Your IP Address?** - - Changing a private IP address does not at all help with Internet address issues. However, changing these makes sense in a few situations: - - - The choice of IP address does not affect your network performance or network security in any meaningful way. **Dynamic Host Configuration Protocol (DHCP)** **DHCP** allows a computer to join an IP-based network without having a pre-configured IP address. DHCP is a protocol that assigns unique IP addresses to devices, then releases and renews these addresses as devices leave and re-join the network. Internet Service Providers (ISPs) usually use DHCP to allow customers to join the Internet with minimum effort. Likewise, home network equipment like [broadband routers](http://compnetworking.about.com/cs/dslcablerouters/g/bldef_bbrouter.htm) offers DHCP support for added convenience in joining home computers to the [LAN](http://compnetworking.about.com/library/glossary/bldef-lan.htm). DHCP environments require a **DHCP server** set up with the appropriate configuration parameters for the given network. Key DHCP parameters include the range or \"pool\" of available IP addresses, the correct [subnet](http://compnetworking.about.com/library/glossary/bldef-subnet.htm) masks, plus [gateway](http://compnetworking.about.com/library/glossary/bldef-gateway.htm) and name server addresses. **VSAT, Modems and Wireless** A **Very Small Aperture Terminal** (**VSAT**), is a two-way [satellite](http://en.wikipedia.org/wiki/Satellite) [ground station](http://en.wikipedia.org/wiki/Ground_station) or a stabilized [maritime Vsat](http://en.wikipedia.org/w/index.php?title=Maritime_Vsat&action=edit&redlink=1) antenna with a [dish antenna](http://en.wikipedia.org/wiki/Satellite_dish) that is smaller than 3 meters. The majority of VSAT antennas range from 75 cm to 1.2 m. Data rates typically range from 56 Kbit/s up to 4 Mbit/s. VSATs access satellites in [geosynchronous orbit](http://en.wikipedia.org/wiki/Geosynchronous_orbit) to relay data from small remote earth stations (terminals) to other terminals (in [mesh](http://en.wikipedia.org/wiki/Mesh_networking) configurations) or master earth station \"hubs\" (in star configurations). VSATs are most commonly used to transmit [narrowband](http://en.wikipedia.org/wiki/Narrowband) data ([point of sale](http://en.wikipedia.org/wiki/Point_of_sale) transactions such as credit card, polling or [RFID](http://en.wikipedia.org/wiki/Radio_Frequency_Identification) data; or [SCADA](http://en.wikipedia.org/wiki/SCADA)), or [broadband](http://en.wikipedia.org/wiki/Broadband) data (for the provision of [Satellite Internet access](http://en.wikipedia.org/wiki/Satellite_Internet_access) to remote locations, [VoIP](http://en.wikipedia.org/wiki/VoIP) or video). VSATs are also used for transportable, on-the-move (utilising [phased array](http://en.wikipedia.org/wiki/Phased_array) antennas) or mobile [maritime](http://en.wikipedia.org/wiki/Ocean) communications. A **MODEM** (modulator-demodulator) is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. The goal is to produce a signal that can be transmitted easily and decoded to reproduce the original digital data. Modems can be used over any means of transmitting analog signals, from driven diodes to radio. The most familiar example is a voice-band modem that turns the digital data of a personal computer into modulated electrical signals in the voice-frequency range of a telephone channel. These signals can be transmitted over telephone lines and demodulated by another modem at the receiver side to recover the digital data. Modems are generally classified by the amount of data they can send in a given time unit, normally measured in bits per second (bit/s, or bps). They can also be classified by the [symbol rate](about:blank) measured in [baud](about:blank), the number of times the modem changes its signal state per second. For example, the ITU V.21 standard used audio frequency-shift keying, aka tones, to carry 300 bit/s using 300 baud, whereas the original ITU V.22 standard allowed 1,200 bit/s with 600 baud using phase-shift keying. In [telecommunications](about:blank), **WIRELESS communication** is the transfer of information without the use of wires. The distances involved may be short (a few meters as in television remote control) or long (thousands or millions of kilometers for radio communications). The term is often shortened to \"wireless\". It encompasses various types of fixed, mobile, and portable [two-way radios](about:blank), [cellular telephones](about:blank), [personal digital assistants](about:blank) (PDAs), and [wireless networking](about:blank). Other examples of *wireless technology* include [GPS](about:blank) units, [garage door openers and or garage doors](about:blank), wireless [computer mice](about:blank), [keyboards](about:blank) and [headsets](about:blank), [satellite television](about:blank) and cordless [telephones](about:blank). **3. Electronic Communication** Electronic communications have developed rapidly over the past 50 years. Over time, communication technologies have evolved as means of overcoming the two principal communication barriers which are (1) **time** and (2) **distance.** Unlike in oral cultures, where people have to be in the same location at the same time to communicate, communication technologies allow data and documents to be created and saved for future reading or transport from one location to another. Electronic communication greatly increases the capacity to overcome barriers of time and distance. In recent years, the use of such electronic media as the telephone, fax machine, electronic mail and electronic conferencing, have made it possible for many people to practice what is known as ***telecommuting**.* Instead of traveling to an office or central location to work, they work out of their homes or other remote locations and "commute" to work electronically. Social networking websites (eg, Facebook, twitters, blogs), email, instant messaging, text messaging and voice mail are just a few examples of electronic communication. **Electronic Text** Although Web-based documents are increasingly common, some electronic text remains limited to the ASCII character set (capital and lower-case letters, numbers, and common symbols), and a significant number of displays use a mono-font (in which all characters receive the same amount of space regardless of their actual width). Although most electronic communication protocols permit the exchange of formatted documents, some email and electronic conferencing software do not. Remember that readability on a computer screen is **not** the same as readability on paper. Text on a screen---especially mono-spaced ASCII text---is more difficult to read than material printed on paper. Material intended to be read on a screen needs to be formatted for *screen* readability. **Formatting Electronic Text** Just as letters, memos, and reports need to be formatted for readability, material prepared for posting on an electronic conference or for sending by electronic mail needs to be formatted for the convenience of the reader. To ensure readability on the screen, the following are important: - - - - - - - **Electronic Mail** Electronic mail is intended to serve as private correspondence between two people or among a specific group of individuals (a mailing *list)* to serve a specific purpose. Although email is a form of written communication and has much in common with business memos and letters, it also has some fairly specific characteristics of which email users should be aware. The following are the most important conventions for effective email messages: - - - - - - - - **Electronic Conferencing** Unlike email, which is essentially private correspondence, an electronic conference is designed to permit the ongoing discussion of specific topics by a group of people. Material posted to an electronic conference is available for all conference members to read. For this reason, messages posted on a conference should be either of interest to other conference members or of possible interest to someone you have not yet identified. **Stay current with course-related postings.** Soon, electronic learning will be the order of the day in the country. Course materials will be posted online or on your server and you will be expected to read them and possibly do your assignments. **The (World Wide) Web** Anybody anywhere in the world who has access to the Internet and a *Web browser* (such as Netscape or Internet Explorer) can read materials posted on the Internet. The Internet now allows exchange of documents containing text and graphics and, with additional software, sounds and video as well. Use of the Internet in general and of the Web in particular has been growing at an exponential rate. **Other Technologies** - - - - **Point of Sale System**  Point of sale (POS) or checkout is the location where a business [transaction](about:blank) occurs. A \"checkout\" refers to a POS terminal or more generally to the [hardware](about:blank) and [software](about:blank) used for checkouts, the equivalent of an electronic cash register. A POS terminal manages the selling process by a salesperson accessible interface. The same system allows the creation and printing of the [receipt](about:blank). Point of sale system hardware include cash drawers, receipt printers, barcode scanners, barcode printers, credit card readers, printer papers and ribbons, barcode labels and ribbons, pole displays, pos keyboards, ID verification devices. Examples of the the software includes Cash Register Express, IC Verify, Barcode Express, Inventory Track Express.