GEN018-1.docx

**MODULE 2 GEN018** Lesson Objectives: At the end of this module, you should be able to: 1\. Identify the computer system and its parts; 2\. Determine the difference of hardware and software; 3\. Identify and define the computer's hardware components; and 4\. Define computer software and its...

**MODULE 2 GEN018** Lesson Objectives: At the end of this module, you should be able to: 1\. Identify the computer system and its parts; 2\. Determine the difference of hardware and software; 3\. Identify and define the computer's hardware components; and 4\. Define computer software and its types. **Information technology (IT)** is a technology which uses computers to gather, process, store, protect, and transfer information. Today, it is common to use the term **Information and** **communications technology (ICT)** because it is unimaginable to work on a computer which is not connected to the network. **The computer consists of:** ** hardware** -- physical computer parts, palpable and visible; and ** software** -- set of commands that are \"understandable\" to the computer. **Basic principle of computers:** **Data** enters the computer through one or more input devices. The **computer** then processes the data and transmits the resulting data to output devices. **Output devices** can be human interfaces such as a screen or another electronic device such as a storage device or computer network. **Parts of a computer (Hardware):** **1. Monitor --** a device that displays the images and texts from your computer. **2. Mouse --** communicates to the computer as a pointing device to icons, which acts as shortcuts to commands to the computer. **3. Printer** -- a device that prints your output, usually documents, to paper. **4. Speaker** -- a device that produces the sound output from the computer. **5. Power Supply --** regulates the power coming into the devices of the computer system. **6. GPU (Graphics Processing Unit) --** also called graphics card, it is an electronic circuit that accelerates the creation of images for output to the screen. **7. Hard Disk --** a device that stores files to your computer for future access. **8. RAM (Random Access Memory) -** a device that stores the data and machine codes for fast retrieval of the processor. **9. Motherboard --** it is where all the computer's devices are connected. It acts as the communication and transfer hub for data and power to the computer's devices. **10.Processor --** also called the **CPU (Central Processing Unit**), is a digital circuit that performs the computations for the computer. **11.Computer Case --** it houses the motherboard, processor, hard disk, RAM, GPU, and power supply safely. **12.Keyboard** -- an input device used to type in the commands to the computer. **Common devices for storing and transferring data:** 1. **Hard disk** 2. **USB flash drive** 3. **Diskettes and ZIP disks** 4. **CD and DVD discs** 5. **Memory cards** 6. **Network drives** 7. **Online/Cloud storage** **Software:** A computer program which, as opposed to hardware, is an intangible part of the computer, written to perform a single or multiple tasks on computer using the built-in hardware. Types of software are the following: **1. Operating System (OS) -** the basic program on your computer that is automatically loaded when computer is started up. Examples are Windows, Mac OS and Linux. **2. Application Software -** some types of software that can be used on an installed operating system that is used to accomplish tasks. Examples are word processors, spreadsheets, games, calculators, virus removal, internet browsers, etc. MODULE 3 Content Notes (13 mins) While the term computer can apply to virtually any device that has a processor in it, most people think of a computer as a device that receives input from the user through a mouse or keyboard, processes it in some fashion and displays the result on a screen. The hardware and software within computers have evolved at a circuit-snapping pace in the past few decades --- the bulky desk-crushing machines from the early \'80s look nothing like the featherweight touchscreen tablets of today. The 10 types of computers are the following: **Personal Computer:** The personal computer (PC) defines a computer designed for general use by a single person. PCs were first known as microcomputers because they were complete computers but built on a smaller scale than the huge systems in use by most businesses. **Desktop:** Until the middle of the 1980s, consumers had one choice for a PC --- and it was the desktop format. The expectation with desktop systems were that you would set the computer up in a permanent location. **Laptop:** These are portable computers that integrate the display, keyboard, a pointing device or trackball, processor, memory and hard drive all in a battery-operated package slightly larger than an average hardcover book. **Netbooks and Tablets:** Netbooks are ultra-portable computers that are even smaller than traditional laptops. The extreme cost-effectiveness means they\'re cheaper than almost any brand-new laptop you\'ll find at retail outlets. However, netbooks\' internal components are less powerful than those in regular laptops. **Tablets** can do pretty much all the functions that laptops do, but don\'t have the internal fans that PCs have. So they have to rely on lower-performing processors that won\'t use as much heat or battery power. They also have less storage capacity than traditional PCs. **Handheld Computers:** Early computers of the 20th century famously required entire rooms. These days, you can carry much more processing power right in your pants pocket. Handheld computers like smartphones and PDAs are one of our era\'s iconic devices. **Workstation:** A workstation is simply a desktop computer that has a more powerful processor, additional memory, high-end graphics adapters and enhanced capabilities for performing a special group of tasks, such as 3D graphics or game development. **Server:** A server is a computer that has been optimized to provide services to other computers over a network. Servers usually have powerful processors, lots of memory and large hard drives. They don\'t typically have dedicated displays, though. Instead, IT workers use a single monitor to configure and control multiple servers, combining their computing power for ever greater speed. **Mainframe:** Mainframes traditionally meant a centralized computer linked to less powerful devices like workstations, this definition is blurring as smaller machines gain more power and mainframes get more flexible. The term mainframe has fallen out of use in favor of enterprise server. You\'ll still hear the term mentioned, though, particularly in large companies to describe the huge machines processing millions of transactions every day. **Supercomputer:** Supercomputers are different from mainframes. Both types of computers wield incredible computing power for Earth\'s most intense industrial and scientific calculations. Mainframes are generally tweaked to provide the ultimate in data reliability. Supercomputers, on the other hand, are the Formula 1 race cars of the computer world, built for breakneck processing speed, so that companies can hurtle through calculations that might take other systems days, weeks, or even months to complete. They\'re often found at places like atomic research centers, spy agencies, scientific institutes, or weather forecasting stations, where speed is of vital concern. **Wearable:** The latest trend in computing is wearable computers. Essentially, common computer applications (e-mail, database, multimedia, calendar/scheduler) are integrated into watches, cellphones, visors and even clothing. Many other wearables target outdoors enthusiasts and fitness freaks, allowing them to track their location, calories burned, steps, speed, and more. MODULE 4 MAIN LESSON Content Notes (13 mins) A **computer network** is a cluster of computers over a shared communication path that work for the purpose of sharing resources from one computer to another, provided by or located on the network nodes. Some of the uses of computer networks are the following: 1. Communicating using email, video, instant messaging, etc. 2. Sharing devices such as printers, scanners, etc. 3. Sharing files 4. Sharing software and operating programs on remote systems 5. Allowing network users to easily access and maintain information **Types of Computer Networks:** **1. Personal Area Network (PAN)** PAN is the most basic type of computer network. This network is restrained to a single person, that is, communication between the computer devices is centered only to an individual's work space. PAN offers a network range of 10 meters from a person to the device providing communication. Examples of PAN are USB, computer, phone, tablet, printer, PDA, etc. **2. Local Area Network (LAN)** LAN is the most frequently used network. A LAN is a computer network that connects computers together through a common communication path, contained within a limited area, that is, locally. A LAN encompasses two or more computers connected over a server. The two important technologies involved in this network are Ethernet and Wi-fi. Examples of LAN are networking in a home, school, library, laboratory, college, office, etc. **3. Wide Area Network (WAN)** WAN is a type of computer network that connects computers over a large geographical distance through a shared communication path. It is not restrained to a single location but extends over many locations. WAN can also be defined as a group of local area networks that communicate with each other. The most common example of WAN is the Internet. **4. Wireless Local Area Network (WLAN)** WLAN is a type of computer network that acts as a local area network but makes use of wireless network technology like Wi-Fi. This network doesn't allow devices communicating over physical cables like in LAN, but allows devices to communicate wirelessly. The most common example of WLAN is Wi-Fi. **5. Campus Area Network (CAN)** CAN is bigger than a LAN but smaller than a MAN. This is a type of computer network which is usually used in places like a school or college. This network covers a limited geographical area that is, it spreads across several buildings within the campus. Examples of CAN are networks that cover schools, colleges, buildings, etc. **6. Metropolitan Area Network (MAN)** A MAN is larger than a LAN but smaller than a WAN. This is the type of computer network that connects computers over a geographical distance through a shared communication path over a city, town or metropolitan area. Examples of MAN are networking in towns, cities, a single large city, large area within multiple buildings, etc. **7. Storage Area Network (StAN)** StAN is a type of computer network that is high speed and connects groups of storage devices to several servers. This network does not depend on LAN or WAN. Instead, a StAN moves the storage resources from the network to its own high-powered network. A StAN provides access to block-level data storage. Examples of StAN are a network of disks accessed by a network of servers. **8. System Area Network (SysAN)** A SysAN is a type of computer network that connects a cluster of high performance computers. It is a connection-oriented and high bandwidth network. A SysAN is a type of LAN that handles high amounts of information in large requests. This network is useful for processing applications that require high network performance. Microsoft SQL Server 2005 uses SysAN through virtual interface adapter. **9. Passive Optical Local Area Network (POLAN)** A POLAN is a type of computer network which is an alternative to a LAN. POLAN uses optical splitters to split an optical signal from a single strand of single mode optical fibre to multiple signals to distribute users and devices. In short, POLAN is a point to multipoint LAN architecture. **10.Enterprise Private Network (EPN)** EPN is a type of computer network mostly used by businesses that want a secure connection over various locations to share computer resources. **11.Virtual Private Network (VPN)** A VPN is a type of computer network that extends a private network across the internet and lets the user send and receive data as if they were connected to a private network even though they are not. Through a virtual point to point connection users can access a private network remotely. VPN protects you from malicious sources by operating as a medium that gives you protected network connection. MODULE 5 **Client/server networks** have centralized servers for storage, which are accessed by client computers and devices. **Peer-to-peer** networks tend to have devices that support the same functions. They are more common in homes, while client/server networks are more likely to be Used by businesses. **Types of Network Connections:** There are also different types of network connections that concern how elements in a network are connected to each other. **Topologies** are used to connect computers, with a collapsed ring being the most common type due to the Ethernet supporting the internet, local area networks and wide area networks. **Star Topology** A **central node** connects a cable to each computer in the network in a star topology. Each computer in the network has an independent connection to the center of the network, and one connection breaking won\'t affect the rest of the network. However, one downside is that many cables are required to form this kind of network. **Bus Topology** In a bus topology network connection, one cable connects the computer. The information for the last node on the network has to run through each connected computer. There is less cabling required, but if the cable breaks it means that none of the computers can reach the network. **Ring Topology** A ring topology is similar to a bus topology. It uses a single cable with the end nodes connected to each other so the signal can circle through the network to find its recipient. The signal will try several times to find its destination even when the network node is not working properly. A collapsed ring has a central node which is a hub, router or switch. The device has an internal ring topology and has places for cable to plug in. Every computer in the network has its own cable to plug into the device. **Key Networking Terms** ** Open system:** an open system is connected to the network and prepared for communication. ** Closed system:** a closed system is not connected to the network and so can\'t be communicated with. ** IP (internet protocol) address:** the network address of the system across the network, which is also known as the Logical Address). ** MAC address:** the MAC address or physical address uniquely identifies each host. It is associated with the Network Interface Card (NIC). ** Port:** a port is a channel through which data is sent and received. ** Nodes:** nodes is a term used to refer to any computing devices such as computers that send and receive network packets across the network. ** Network packets:** the data that is sent to and from the nodes in a network. ** Routers:** routers are pieces of hardware that manage router packets. They determine which node the information came from and where to send it to. A router has a routing protocol which defines how it communicates with other routers. ** Network** **address translation (NAT):** a technique that routers use to provide internet service to more devices using fewer public IPs. A router has a public IP address but devices connected to it are assigned private IPs that others outside of the network can\'t see. ** Dynamic host configuration protocol** (DHCP): assigns dynamic IP addresses to hosts and is maintained by the internet service provider. ** Internet service providers (ISP):** companies that provide everyone with their internet connection, both to individuals and to businesses and other organizations.