1702923359491-Basics Computer Literacy.pdf

Chapter 1: Computer Fundamentals Part 1: COMPUTERS AND OPERATING SYSTEMS A. What is a Computer? A computer is an electronic device that receives data (input), processes data, stores data, and produces a result (output). A computer’s basic parts are made up of the system unit, keyboard,...

Chapter 1: Computer Fundamentals Part 1: COMPUTERS AND OPERATING SYSTEMS A. What is a Computer? A computer is an electronic device that receives data (input), processes data, stores data, and produces a result (output). A computer’s basic parts are made up of the system unit, keyboard, monitor and mouse. Figure1.1. Figure 1.1: Basic Parts of a Computer B. Computer system A computer system is made up of multiple electronic components that consist of four broad categories, serving in the information processing cycle. Figure 1.2. Figure 1.2: The Information Processing Cycle 6   Input: Those components helping the user to key in the data to the computer, like keyboard, mouse and touchscreen.  Processing: Those components moving and processing the data inside the computer, like CPU, memory, sound card, and other components inside the system unit.  Storage: Those components storing the software and data until it is needed, like hard drive, USB flash drive and optical device.  Output: Those components providing the results of processing to the user, like the monitor, projector, and printer. C. Characteristics of Computers Characteristics of computers are as follows:  High Speed: computers are very fast and can calculate large amount of data, they can perform millions or billions of calculations in a fraction of a second (i.e. microsecond, nanosecond or picosecond).  Storage: computers use different types of memory storage to keep data and information. Some storage can keep large amount of data and other storage can recall the data very fast.  Accuracy: computers are completely accurate; this means they make calculations those are 100% error free. Computers error usually come from a data input error or a software error.  Reliability: computers are reliable machines, where the hardware and software components perform consistently according to their specifications for a long period. They are also designed to be easily maintained.  Versatility: computers are very versatile and can perform multiple tasks simultaneously with equal ease.  Diligence: computers do not have any human traits, therefore, they do not feel any tiredness or lack of concentration. They can work continuously without errors, with the same speed and accuracy.  Resource sharing: computers can connect to other devices and share their resources or vice versa. They can connect to printers and share with others. A computer’s hard drive can also be shared with other computers. 7 D. Benefits and Usage of Computers Computers are powerful and useful tools and provides many useful benefits, such as its capability to produce high quality task within a short span of time. Computers can be used to learn a wide range of skills those are important in today’s technological world. The general benefits and uses of computers are as follows:  Business: companies are making computers part of their business organization. They are used for payroll, sales, budget planning, financial, management information system, etc.  Banking: banks are dependent on computers. They offer online transaction facilities to track bank records such as loans, account statements, interest charges, credit cards and other services. They provide Automated Teller Machine (ATM) and Cash Deposit Machine (CDM) for faster financial operations and 24-hours availability.  Government: computers play an important role in government. They are used in different areas of the government such as passport and visa systems, driving licensing, traffic systems, national ID system and many more.  Military: computers are widely used in defense and today most military weapons have computerized control systems.  Heath Care: hospitals use computers to keep patients health records and medicine history. Most of the equipment used in the hospital laboratories have computerized control systems.  Education: computers have provided a lot of benefits in the education system. They are vital tools in the E-learning system, student information system, teacher and student evaluation system and others.  Communication: communication is a way of conveying the messages. Today’s computer technologies help people to communicate easily. E-mail, chatting and video conferencing are the most commonly used applications in communication.  Home Computer: every home uses computers in different ways, such as entertainment, Internet connectivity, security system and even household appliances are operated by computer systems. 8 E. Types of Computer  Mainframes A mainframe computer is a powerful computer designed for processing huge amounts of data for hundreds or thousands of users at the same time. Supercomputers A supercomputer is a very powerful computer distinguished by its processing capacity, especially its speed of calculation. They have processors with a million or more cores, and are used primarily for scientific applications that need to perform complex calculations very rapidly. Servers Servers are dedicated to handling data with minimal user interaction.They do not include optical storage devices, speakers, high-end graphic displays, or other peripherals. A basic server can have processing, memory, and storage capabilities similar to a powerful desktop computer. As the number of server users increases, servers must be able to increase their processing capacity to handle the additional data, a feature called scalability. 9  Microcomputers or PCs (Personal Computers): are small and inexpensive, designed for a single user. They are centered on the microprocessor technology that allows the manufacturers to fit in an entire CPU within a single chip. Although, they are designed for a single-user those can be linked to other device to form or join a network computer. There are different types of microcomputers, such as: – Desktop Computers A desktop computer is a computer that fits on or next to a desk. The system unit containing the processing components is called a tower. An all-in-one desktop houses the processing components in the same case that holds the monitor; there is no tower. – Laptop Computers A laptop computer (sometimes called a notebook) is a lightweight mobile computer about the size of a paper notebook that includes the system components, keyboard, pointing device, and display screen in a single unit. Netbook computers (also called ultrabooks) look like laptops but are smaller and lighter. They have less power and storage capacity, lack a CD/DVD drive, and provide a smaller keyboard and display screen than laptops, but they include batteries that hold a charge longer. Netbooks are suitable for mobile users who access the Internet frequently or for long periods of time and don’t need to store a lot of data or software on a hard drive. 10 – Tablet Computers A tablet computer is a one-piece handheld computer that typically includes a touchscreen. Convertible tablets use a hybrid design that includes a swivel screen or removable keyboard. – Smartphones A smartphone is a cell phone that includes many features of a computer. Smartphones connect wirelessly to the Internet; include built-in cameras, music players, and global positioning systems (GPSs); and let you send and receive phone calls, e-mail, messages, and text messages – Other Mobile Devices Mobile devices besides laptops, tablets, and smartphones include electronic book (e-book) readers, portable media players, and handheld game devices 11 Part 2: COMPUTER HARDWARE A. The System Unit The heart of any computer is its system unit that is the main body of the computer, containing all essential components, required for its functioning. The system unit houses a computer’s processing hardware, including the motherboard. 1. Motherboard: It is the major circuit board, on which all components are placed and connected. It contains Central Processing Unit, RAM, ROM, connectors, HDD, CD/DVD/BD, expansion slots, network interface card etc. 2. Expansion Slot Circuit boards called expansion cards or adapter cards can be plugged into expansion slots on the motherboard of a desktop or server computer. Expansion cards expand the capabilities of the computer or let you attach a peripheral device to the computer. 3. Central Processing Unit The central processing unit (CPU) is a single computer chip that contains all the electronic circuitry a computer needs to process data. Each computer has one processor at the minimum, which is called Central Processing Unit (CPU), brain or virtual brain of the computer. It accomplishes all kinds of tasks like information processing, storing, accessing, and instruction processing. It also controls all parts of the computer. 12  Shows the most common type of computer processor, Intel and AMD processors. Example (Intel Core i3, i5, i7 and i9). Parts of a CPU  The arithmetic/logic unit (ALU) performs arithmetic calculations and logical operations.  The control unit coordinates all the processor’s activities and manages the flow of information through the processor.  Registers are memory cells for temporarily storing data needed by the ALU to perform its calculations. CPU Performance Factor  The performance of CPU relates to some of the following factors:  The CPU maximum speed, which is measured in billions of hertz (cycles per second) or gigahertz (GHz). Gigahertz means 1,000,000,000=109 Hertz.  Another factor is the CPU word size, which is the number of bits that the CPU (per core if it is multi-core) can accept as input simultaneously. CPUs usually have 32-bit or 64-bit word size.  An additional factor will be the number of Cores and Cache designs. 4. Memory The CPU, operating systems, and applications use memory (chips inside the system unit) to store data and instructions. A computer has two types of memory: volatile and nonvolatile. RAM is volatile memory that loses its contents when you turn off the computer.ROM is nonvolatile memory because it is permanent; it does not lose its contents when you turn off the computer. Classification of Memory  RAM (Random Access Memory): Data, information, and instructions from applications and the operating system are stored temporarily in RAM. RAM usually consists of several chips on a circuit board called a memory module, which is plugged into the motherboard. 13   ROM (Read-Only Memory): stored on a single chip on the motherboard. The operating system retrieves data or programs in ROM when it needs them and does not write over the contents of ROM. 5. Heat Sinks and Fans Processors in laptops, desktops, and servers generate a lot of heat. As the temperature increases, the system slows down to avoid overheating, which severely impairs performance. To prevent overheating, one or more fans in the system unit draw cooler air into the case from the outside and expel warm air from the inside. The fan moves air across a heat sink, which collects heat from an electronic component so the fan can cool it quickly. You can tell how efficiently a computer is working by tracking its CPU and RAM usage. You can track the CPU and RAM usage in Windows by using Task Manager. Task Manager gives you a behind-the-scenes glimpse at how Windows is interacting with hardware resources and other software 14 6. Power Supply: It is used to convert AC power to low- regulated voltage DC power that can be supplied to the components of the computer system. It is a large silver metal box mounted in one corner of the system unit, with many bundles of colored wires and connectors. Each wire carries a different voltage. Each connector has appropriate wires to deliver the exact voltage required. 7. Ports and Buses: A port is a connector located on the system case that you use to plug peripheral devices into the computer. Inside the system unit, a port is attached to a bus on the motherboard. A bus is a sequence of electronic circuitry used to transfer data among computer components. Peripheral devices use a bus, sometimes called an expansion bus, to exchange data with the motherboard. Types of ports on computing devices: o Universal Serial Bus (USB): is most common multipurpose port that connects all types of external devices such as hard disk, flash disk, printer, scanner, digital camera, mouse, keyboard and even smartphones. o Audio: Connects speakers, headphones, and microphones o RJ-45:Connects the computer to a wired network using an Ethernet cable 15  o Video Graphics Array (VGA) and High-Definition Multimedia Interface (HDMI): Standards for connecting display monitors o FireWire, or IEEE 1394, which was developed by Apple as a high-speed method for connecting multimedia devices such as video cameras to a computer. A single FireWire port can accommodate many external devices. B. Input Devices An input device is a peripheral device you use to enter data and commands into a computer. 1. The keyboard is the most common input device for entering text and numbers into a computer. Keyboards can be built into the computer, attached using a cable, or connected using a wireless connection. 2. A pointing device is an input device you use to position the pointer on the screen. The pointer appears as an arrow, I-beam, or other shape. You use the pointer to select onscreen objects such as text, graphics, buttons, icons, and links. Types of pointing devices  A mouse is a pointing device that fits comfortably in the palm of your hand. Popular types of mice are optical, wireless, and touch 16  A touchpad (also called a trackpad) is a touch-sensitive surface that can convert the motion and position of your fingers to a relative position on screen.  A pointing stick is a pressure-sensitive device that resembles a pencil eraser.  A trackball is a pointing device that works like a mouse with a ball on top of the device. 17  Touchscreens: Many mobile computers use touchscreens, which have a touch-sensitive surface that overlays the screen and responds to the electrical impulses in your fingertips  Digital Pens: A stylus is a pen-like writing instrument that works with touchscreens. 18 3. Audio Input Devices  Audio input is sound entered into a computer, and includes speech, sound effects, and music. Mobile phones and hands-free navigation systems in motor vehicles use voice-recognition systems. 4. Game Controllers: The joystick and wheel are types of pointing devices you use when playing games, or as adaptive equipment when you need an alternative to a mouse. 5. Scanners: are devices that can change images into codes that the computer accepts as input. The quality of a scanner is measured by pixels per inch (ppi); the higher the ppi number, the better the input image. Types of scanners:  Flat-bed scanners: These devices convert printed documents and images into an electronic object that you can store in a computer’s memory.  Bar code scanners: A bar code is a matrix or series of lines with varying widths and heights that represent letters and numbers.  Radio frequency identification (RFID) readers: RFID readers scan the codes stored in an RFID tag, a tiny chip with a radio antenna that can be attached to almost anything. RFID readers can scan many tags at once.  Magnetic scanners: These devices read encoded information on credit cards. The magnetic strip on the back of each card contains the user’s encoded account number. 19   Wireless scanners: These scanners use Bluetooth wireless technology to scan bar code data, such as from a hospital bracelet, and transmit it to a computer.  Optical character recognition (OCR) and optical mark recognition (OMR): These devices use a light source to read characters, marks, and codes; the data is then converted into a digital format. Banks use OCR technology to scan checks. Commonly known as Scantrons, schools and other organizations use OMR for testing purposes. 6. Biometric Devices  Biometrics is a security technique using automated methods of recognizing a person based on a physical characteristic. 20 C. Output Devices Output devices make the computer’s processed information available to the user. 1. Display Screen: is a video screen that the computer uses to provide information to a user. It can be built into a device as with smartphones, tablets and notebook PCs or can be a separate unit as a monitor with a desktop computer. Types of display screen:  A monitor: The most popular technology for computer monitors is the liquid crystal display (LCD) technology, which manipulates light with a layer of liquid crystal cells to produce an image.LCD screens are lightweight, display images clearly, and use energy efficiently.  A projector also called a data projector, which connects to a computer and projects images onto a wall screen or other large, flat surface. Small computer projectors use LCD or digital light processing (DLP) technology, which bounces lights off microscopic mirrors on a computer chip. 2. Printers produce a paper copy, or hard copy, of processing results.When selecting a printer to purchase, consider the following features:  Speed—Measured in pages per minute (ppm)  Print quality—Measured in dots per inch (dpi)  Price—Includes the original cost of the printer and what it costs for the ink or toner. Types of Printers:  An inkjet printer is a nonimpact printer that creates text and images by spraying ink onto paper.  A laser printer is a nonimpact printer that creates text and images using the same technology as copier machines. As a light-sensitive drum revolves in the printer, a laser beam etches text and images on the drum as a pattern of electrical charges. The printer then coats the drum with toner. 21   Specialized Printers Other types of printers are available, including the following:  Thermal—Forms characters by heating special heat-sensitive paper  Mobile—A small, battery-powered printer, primarily used to print from a mobile computer  Label and postage—Prints labels of various types and sizes on paper that contains adhesive on one side  Plotters and large format—Used for drawings and drafting output  3D Printer is new technology in printing that uses plastic resin, rather than ink. It lays down layers of plastic in a particular arrangement to produce a 3D object. 3. Audio Output Devices: Speakers, headphones, and earbuds are other types of output devices 22 D. Storage Media and Devices A storage device is where programs and data are stored or written for a long period of time or permanently. It is also used for carrying data from one computer to another. It is not accessible directly to the CPU that is why slower for read/write operation. It is cheap and used for large data storage. We can compare storage media based on the following characteristics:  Capacity—The maximum amount of data a medium can store  Speed—Measured by access time and the data transfer rate  Access time is the average number of milliseconds (ms) it takes a computer to retrieve data from the storage device.  The data transfer rate determines how much data the storage device can move per second from the storage media to the computer. Types of Storage Devices  Magnetic Tape: stores the digital information in the form of recording. It is packed in cartridge and plastic case. It could store up around 100 TB of data.  Hard Disk Drive (HDD) is the main storage device in a computer. Hard drives contain a stack of disks made of aluminum or glass that are coated with magnetic iron oxide particles.  Optical Disk Drive: uses lasers to read and write data on plastic platters that contain a metal layer, which reflects the laser light back to a sensor in an optical drive. 23  Types of Optical Disk  Compact Disk (CD) is oldest and most basic type, which can hold up to of 700MB of data.  Digital Versatile Disk (DVD) is a single layer single-sided DVD can store up to 4.7GB, the Dual Layer-single sided DVD can store up to 8.5GB and the Dual-layer double-sided DVD can hold up to 17GB of data.  Blu-ray Disk (BD) is a disk that can store High Definition (HD) videos, including 3D videos. It can store up to 25GB in a single layer, 50GB on a dual-layer, 100GB and 128GB on a BD-XL format.  External hard drive is a separate, freestanding high-capacity storage device that you attach to a computer, usually using a USB port. External hard drives can use magnetic or solid-state technology. Portable Drives: use the same solid-state technology as internal SSDs do. The smallest types are collectively called memory cards. USB flash drives are another type of solid-state storage media.  A solid-state drive (SSD) uses flash memory technology to store data as electrical rather than magnetic charges. SSDs have no moving parts, so they are more durable and reliable than mechanical hard drives. They consume less power, generate less heat, and retrieve data more quickly, making them a good alternative for tablets and other mobile devices. 24 Part 3: COMPUTER SOFTWARE A program that is made to accomplish a particular task is called software. A program is a series of commands written to find the solution of a specific problem. A programmer writes the instructions that become computer programs. The programmer writes line-by-line using programming language, and then compiles those instructions into usable programs. A. Types of software A computer relies on two types of software: 1. System Software 2. Application Software – System Software and Application Software 1. System software runs a computer. System software includes: a. The BIOS is a permanent program inside the ROM, which stands for (Basic Input/output System). When computer is turned on, the booting process start in black screen and the BIOS automatically run and performs a power-on self-test (POST) function, which is part of the BIOS program. The POST ensures that all critical hardware devices are functioning properly, including the CPU, RAM, and the motherboard. b. Operating System is software that coordinates the resources and activities on a computer. The operating system performs these important functions:  Provides the user interface that we use to communicate commands and receive feedback.  Performs the communication with hardware, instructs it for necessary actions to accomplish task.  Runs the programs and facilitates the user to use these programs.  Performs the controlling and management for the file storage. Operating systems fall into four major categories depending on the type of device for which they are designed: o Personal computers o Mobile computing devices o Servers 25  o Devices other than computers Examples of operating systems are Unix, Linux, Mac OS, Microsoft Operating Systems (MS-DOS, Windows 3.1, 95, 98, 2000, NT, XP, Vista, 7, 8, 10) and also includes Android and IOS for mobile phones c. System Utilities that add many maintenance functions.it helps the operating system set up, maintain, and protect a computer. These programs work together with operating system and perform services that keep OS running smoothly System utilities are developed to customize, analyze, configure and maintain a computer. Microsoft Windows comes with built-in system utilities. Other utilities are needed to be installed. Examples are Anti-virus, Backup and Restore, Data compression, Disk cleaners, File managers, and many more. So we can say it performs housekeeping tasks on computer. d. Device Drivers. Device Driver is a type of system software that is used to control a particular hardware. The manufacture of hardware such as HP printer writes the driver software for a particular operating system that comes in an optical disk (CD/DVD) or provided at manufacturer’s website, to download it from the internet. Once Device Driver is installed, it will work with OS to make sure the device works correctly. Device driver controls and manages hardware devices and tells the computer how the device is working. 2. Application Software It is a software designed to accomplish a range of coordinated functions, tasks or activities that benefits the user. It is also called end-user programs. Categories of Application Software  General Purpose Software: is also called as “off-the shelf” software (ready-made), which is used by lots of people and for a variety of task. It is also called “Package software”, like: word processors, spreadsheets, graphical designing software, databases, desktop publishing software, multimedia applications, and web browsers, etc. 26   Custom Software: is designed and developed for a specific user and purpose. It is also called “Tailor-made software”. Examples include: the software used by the military, missile operation, hospital application software, banking system software and many more.  Other Application Software – Programming Language: is a software used to create programs, controls the behavior of a machine or to express an algorithm. Java, C++, Visual Basic, Python and Ruby are examples of a programming languages. Each programming language needs a compiler or interpreter to convert the source code from a programming language into a machine code, which the computer can understand. The compiler scan the whole program, if there is not any error the source code translated as a whole to machine code while interpreter translates source code line by line. Compilers used by: Visual Basic, C++, while interpreter used by: Python and Ruby – Virus: is a type of malicious computer program, when entered and activated in a system, duplicate and reproduce (replicates) itself, could harm other programs  Worms Virus: is a tiny pieces of program that uses computer networks and security holes for its replication.  Trojan Horse: is sent to our computer hidden inside another program. It impersonates itself to make us trust that it is an essential and beneficial program.  Email Virus: is a type of program that uses the emailing system to transmit the viruses.  Boot Sector Virus: infects the master boot record, and activates it during the boot-up process.  Memory Resident Virus: infects the computer memory and gets activated when the operating system starts. Any opened file would be infected.  Overwrite Virus: infects a file and deletes the data inside it. After its activation, the file could be partly completely useless. The file would remain same but the contents could be replaced.  Ransomware: is a type of malicious software that blocks the access and doesn’t allow a user to enter the personal computer system, and the user needs to pay an asking amount to the hacker, to get an entry code. Our screen could come up with a notice, 27  informing us that our computer has been locked and we could get the access after the required payment. CryptoLocker and CryptoWall are the examples of ransomware. – Antivirus: is a type of software which has been developed to detect and remove computer viruses. When updated regularly, it will protect the computer from new known viruses. Examples are Kaspersky, Avira, and Panda Cloud etc. B. Software Management  Installing software A setup program is included with the software to guide you through the installation steps and prepare the software so you can use it on your computer. The method you use to install software depends on the type of personal computer you are using, the type of software you are installing, and how it is distributed. You typically install four types of software: desktop applications, Windows 8 apps, mobile apps, and utility programs such as drivers and system tools.  Uninstalling software To uninstall a desktop application from a Windows computer, you use an uninstaller, which is a tool similar to a setup program that completely removes software from your system. To uninstall a Windows 8 app or mobile app, you use an Uninstall command. When you use an uninstaller, it deletes the software’s files, restores system settings, and restores the graphical user interface. 28 C. Preparing to Purchase a Computer The quality of a computer is determined primarily by the performance of its system components. Factors to consider in purchasing a computer:  Purpose: it is important to consider the task that you want to perform on the PC.  Price: one of the most important factors is your budget; how much money to invest in a PC?  Operating System: most of the PCs and Notebooks are bundled with a minimum requirement for the operating system such as Windows Home edition.  Size: we need to decide which size of PC is needed; a notebook which we can take anywhere or a desktop which we will be using at home or in the office.  Processor: it is important to consider the processor which is installed in the PC.  Memory: memory will affect the computers multitasking efficiency and its speed of operation.  Storage: there are different options that we need to consider for the hard drive. This decision is depending on the reason, why we are going to use the PC?  Brand: some brands come with attractive packages, such as warranty and software package.  Warranty: is an important consideration while buying a new computer. Warranty is an after sales support from the PC company so that if something happens to the PC, either they will repair or replace it with a new PC. 29