مـلخـص الـشـابـتـر 1 IT مـع تـرجـمـة الـمصـطـلـحـات ..pdf

# Computer system components and their functions A computer is an electronic machine designed to accept data, store it, process it according to instructions, and produce results as information. The fundamental building blocks of a computer system can be broadly categorized into input devices, output devices, processing units, and storage devices [3](#page=3). ### 1.1 Data vs. Information * **Data:** Refers to raw, unorganized facts that require processing to become meaningful [4](#page=4). * **Information:** Is the result of processing, organizing, structuring, or presenting data in a context that makes it useful and understandable to humans [4](#page=4). ### 1.2 Core Computer Components The essential parts of a computer system include the system unit, monitor, keyboard, and mouse [5](#page=5). #### 1.2.1 System unit The system unit is a case that houses the critical components of the computer, such as the motherboard, Central Processing Unit (CPU), Random Access Memory (RAM), and other internal parts [5](#page=5). #### 1.2.2 Monitor A monitor functions as an output device, displaying graphical and textual output that is understandable to the user [5](#page=5). #### 1.2.3 Keyboard The keyboard is an input device used for entering text, characters, and commands into the computer by pressing keys [17](#page=17) [5](#page=5). #### 1.2.4 Mouse A mouse is a pointing device used as an input device to interact with graphical elements on the screen, allowing users to select, click, and move objects [5](#page=5). ### 2. Hardware Hardware refers to the physical components of a computer. This includes input devices, output devices, the CPU, motherboard, power supply, RAM, and other constituent parts [10](#page=10). #### 2.1 Motherboard The motherboard is the main circuit board of the computer, serving as the central hub where most components and peripheral devices are connected [11](#page=11). #### 2.2 Central Processing Unit (CPU) The CPU, also known as the microprocessor or processor, is the core component of the computer system and is often referred to as the "brain" of the computer. It is responsible for executing instructions and processing data [11](#page=11). ##### 2.2.1 CPU speed Processor speed is measured in Hertz [12](#page=12). ##### 2.2.2 Parts of the processor The CPU consists of several key parts: * **Arithmetic Logic Unit (ALU):** Performs arithmetic operations (like addition, subtraction, multiplication, and division) and logic operations (such as comparisons) [12](#page=12). * **Control Unit (CU):** Directs and manages all operations within the processor [12](#page=12). * **Registers:** These are temporary storage areas within the CPU used to hold data and instructions during processing [12](#page=12). ##### 2.2.3 How the processor works (Machine Cycle) The CPU executes instructions through a machine cycle, which involves four primary operations: fetching, decoding, executing, and storing [13](#page=13). 1. **Fetching:** Retrieving instructions or data from memory [13](#page=13). 2. **Decoding:** Translating the fetched instructions into signals that the computer can understand and execute [13](#page=13). 3. **Executing:** Carrying out the command or instruction [13](#page=13). 4. **Storing:** Writing the results of the execution back to memory [13](#page=13). ### 3. Memory Memory is crucial for computer operations, broadly categorized into primary and secondary memory. #### 3.1 Primary Memory Primary memory, often referred to as main memory, is where the operating system and applications are loaded for quick access. Data stored in primary memory is temporary [14](#page=14). * **RAM (Random Access Memory):** RAM is the main memory of the computer. It is volatile, meaning data is lost when the power is turned off [14](#page=14). * **ROM (Read-Only Memory):** ROM is a non-volatile memory that permanently stores essential system instructions and data. Its content cannot be changed by the user, making it ideal for firmware and boot instructions [15](#page=15). #### 3.2 Secondary Memory (Storage Devices) Secondary memory, or storage devices, are non-volatile and persistent, meaning data is retained even when the power is off. These devices are not directly accessed by the processor but are used for long-term data storage [30](#page=30). * **Hard Disk Drive (HDD):** The primary large-capacity storage area for operating systems, applications, and user data [31](#page=31). * **Solid State Drive (SSD):** Uses non-volatile flash memory chips for data storage, offering faster performance than HDDs [31](#page=31). * **Compact Disc (CD):** A common type of removable media, suitable for music and data storage [32](#page=32). * **Digital Versatile Disc (DVD):** Similar in dimensions to a CD but with a higher storage capacity, commonly used for transferring digital video [32](#page=32). * **Blu-ray Disc (BD):** A digital optical disc capable of storing hours of high-definition and ultra-high-definition video [33](#page=33). * **USB Flash Drive:** A portable flash memory storage device integrated with a USB connector, typically small, lightweight, and rewritable [34](#page=34). * **External Hard Disk:** An external storage device that connects via USB, generally having slower data transfer rates compared to internal hard disks [34](#page=34). ### 4. Input Devices Input devices are hardware components that provide data and send instructions to the computer [16](#page=16). #### 4.1 Examples of Input Devices * **Keyboard:** Used for inputting text and characters via keys [17](#page=17). * **Pointing Devices:** * **Optical Mouse:** Uses lasers or LEDs to track movement [18](#page=18). * **Trackball:** A pointing device with an exposed ball that detects rotation [18](#page=18). * **Touchscreen:** Allows interaction by touching the screen with a finger or stylus [18](#page=18). * **Game Controller:** Used for input in video games and entertainment systems [19](#page=19). * **Image Scanner:** Captures images from documents, text, or objects and converts them into a digital format [20](#page=20). * **Webcam:** A low-resolution video camera for visual input easily transferable over the internet [20](#page=20). * **Digital Camera:** Captures pictures or video, storing them on its memory card [21](#page=21). * **Fingerprint Scanner:** Identifies and authenticates fingerprints for access control [21](#page=21). * **Microphone:** A sound sensor that converts sound into electrical signals [22](#page=22). * **Barcode Reader:** Reads barcodes, often using a laser, commonly found in supermarkets [22](#page=22). * **Magnetic Ink Character Recognition (MICR):** A technology that recognizes characters printed with special magnetized ink, widely used in banks [23](#page=23). * **Optical Character Reader (OCR):** Converts images of letters or typed text into computer-readable data [24](#page=24). * **QR (Quick Response) Code Reader:** Scans two-dimensional barcodes to access stored information, often through smartphone apps [25](#page=25). ### 5. Output Devices Output devices are hardware components that communicate the results of data processing to the user [26](#page=26). #### 5.1 Examples of Output Devices * **Monitor (Visual Display Unit - VDU):** Displays information in a human-understandable format [27](#page=27). * **Printers:** Produce hard copies of information on paper. Types include Dot-Matrix, Ink-Jet, and Laser printers [27](#page=27). * **Plotters:** Similar to printers but typically used for printing larger images [28](#page=28). * **3D Printer:** Creates physical objects from digital models by layering materials [28](#page=28). * **Speakers:** Generate sound output by connecting to the computer [29](#page=29). * **Projector:** Projects images or videos onto a surface, such as a screen [29](#page=29). ### 6. Units of Memory Capacity * **Bit:** The smallest unit of data, holding a single binary value (0 or 1) [35](#page=35). * **Byte:** Consists of eight bits [35](#page=35). * **Kilobyte (KB):** 1,024 Bytes [36](#page=36). * **Megabyte (MB):** 1,024 KB [36](#page=36). * **Gigabyte (GB):** 1,024 MB [36](#page=36). * **Terabyte (TB):** 1,024 GB [36](#page=36). #### 6.1 Converting Storage Capacities to Bytes Conversions are performed using the relationship where 1 Kilobyte equals 1024 bytes. * 1 MB = $1 \times 1024 \times 1024 = 1,048,576$ bytes [37](#page=37). * 5 TB = $5 \times 1024 \times 1024 \times 1024 \times 1024$ bytes [37](#page=37). * 3 GB = $3 \times 1024 \times 1024 \times 1024$ bytes [37](#page=37). * 7 KB = $7 \times 1024 = 7,168$ bytes [37](#page=37). --- # Classifications of computers and software types This topic categorizes different types of computers based on their design and portability, and distinguishes between system software and application software, providing examples of each. ### 2.1 Classifications of computers Computers can be classified based on their size, power, and intended use, ranging from personal devices to powerful supercomputers. #### 2.1.1 Desktop computers A desktop computer is a personal computer designed to fit on a desk. It typically comprises a system unit, a keyboard, a mouse, and a monitor [6](#page=6). #### 2.1.2 Laptop computers A laptop computer is a portable computer with an integrated screen and keyboard. It is battery-powered, making it more portable than a desktop computer [6](#page=6). #### 2.1.3 Tablet computers A tablet computer is a handheld computer that is more portable than a laptop. Instead of a keyboard and mouse, tablets utilize a touch-sensitive screen for typing and navigation [7](#page=7). #### 2.1.4 Smartphones A smartphone is a more powerful version of a traditional cell phone, featuring a touch-sensitive screen [7](#page=7). #### 2.1.5 Servers A server is a software or hardware device that accepts and responds to requests made over a network. The device making the request and receiving the response from the server is known as a client [8](#page=8). #### 2.1.6 Mainframe computers A mainframe computer is a very large and expensive computer capable of supporting hundreds, or even thousands, of users simultaneously [9](#page=9). #### 2.1.7 Supercomputers A supercomputer is the fastest and most powerful type of computer. These are employed for specialized applications that require immense amounts of mathematical calculations, such as weather forecasting, nuclear energy research, and petroleum exploration [9](#page=9). ### 2.2 Software types Software refers to the set of instructions (programs) that enable a computer to function. Software can be broadly categorized into system software and application software [38](#page=38). #### 2.2.1 System software System software is a special type of program that loads automatically when a computer starts up. Its primary role is to control or maintain the operations of the computer and its connected devices [39](#page=39). ##### 2.2.1.1 Operating systems An operating system is a system software that allows users to run other applications on a computing device. It also communicates with hardware devices and manages file storage. Examples include Windows, Mac OS, Linux, and Android [40](#page=40). ##### 2.2.1.2 Utilities software Utilities software is a type of system software that adds functionality to a computer or helps it perform better. This category includes antivirus programs, backup software, disk repair tools, file management utilities, and file compression tools. Examples include Kaspersky, McAfee, Norton, WinZip, and WinRAR [41](#page=41). ##### 2.2.1.3 Device drivers A device driver is a type of system software designed to enable interaction between a hardware device and the operating system or programs that use it. Without a device driver, the hardware device will fail to work. Many hardware devices require drivers, such as printers, graphic cards, sound cards, network cards, and modems [42](#page=42). > **Tip:** Understanding the layered interaction between hardware, device drivers, the operating system, applications, and the user is crucial for comprehending how a computer system functions [42](#page=42). #### 2.2.2 Application software Application software is designed to make users more productive and assist them with personal tasks [39](#page=39). > **Example:** Common examples of application software include word processors like Microsoft Word, spreadsheet programs like Microsoft Excel, presentation software like Microsoft PowerPoint, database management systems like Microsoft Access, calculators, web browsers, image editing software like Adobe Photoshop, and games [43](#page=43). #### 2.2.3 Proprietary software Proprietary software is any software that is copyrighted and has limits imposed by its publisher, vendor, or developer regarding its use, distribution, and modification [48](#page=48). #### 2.2.4 Open-source software Open-source software is developed by many individuals and is distributed in a way that grants all rights to use, modify, and share the software in both modified and unmodified forms [48](#page=48). > **Tip:** In 2010, Oman launched a national initiative for Free and Open-Source Software (FOSS) with objectives including presenting FOSS as a viable alternative to proprietary software, developing IT solutions based on FOSS, and encouraging the public to use FOSS to reduce the use of unlicensed software [48](#page=48). --- # Software licensing and usage agreements This topic examines the various legal frameworks and agreements that govern how software can be used, distributed, and modified. ### 3.1 Software copyright Software copyright is a legal mechanism commonly employed to protect computer programs. It grants the creator exclusive rights to reproduce, distribute, and create derivative works of their software. Proprietary software companies extensively utilize copyright to prevent unauthorized duplication of their products. Interestingly, even open-source licenses rely on copyright law to enforce their specific terms and conditions. Software licenses can be structured based on various factors, including the number of users, the type of users, the quantity of computers, and the size of the institution [45](#page=45). ### 3.2 End-user license agreement (EULA) An End-User License Agreement (EULA) is a binding legal contract established between the software manufacturer or author and the end user of an application. This agreement meticulously details the permissible uses of the software and outlines any restrictions imposed by the manufacturer. The end user is presented with the option to either accept or reject the terms of the EULA, often leading to users agreeing to the terms without thoroughly reading them. The installation process for the software is typically contingent upon the user explicitly clicking an "Accept" button, signifying their consent to the EULA [46](#page=46). ### 3.3 Types of software licenses This section explores several common models of software distribution and usage. #### 3.3.1 Shareware Shareware refers to proprietary software that is provided to users on a trial basis without requiring upfront payment. After the trial period concludes, the program may cease to function until a license is purchased. Common examples of shareware include Microsoft Office and Adobe Photoshop [47](#page=47). #### 3.3.2 Freeware Freeware is software that can be fully utilized for an unlimited duration without incurring any cost. However, the author of freeware typically retains certain rights and may restrict one or more of the rights to copy, distribute, or create derivative works from the software. Popular examples of freeware include Mozilla Firefox and Google Chrome [47](#page=47). #### 3.3.3 Proprietary software Proprietary software encompasses any software that is protected by copyright and carries limitations on its use, distribution, and modification. These restrictions are imposed by the publisher, vendor, or developer of the software [48](#page=48). #### 3.3.4 Open-source software Open-source software is developed collaboratively by numerous individuals and is distributed in a manner that grants all users the rights to use, modify, and share the software. This includes the right to distribute the software in both its original and modified forms [48](#page=48). ##### 3.3.4.1 FOSS initiative in Oman In Oman, a national initiative for Free and Open-Source Software (FOSS) was launched in 2010. This initiative has several key objectives, including [48](#page=48): * Presenting FOSS as a viable alternative to proprietary software [48](#page=48). * Developing information technology solutions that are based on FOSS [48](#page=48). * Encouraging the general public to adopt FOSS to reduce the incidence of using unlicensed software [48](#page=48). --- # Factors for choosing a computer and ergonomics This topic explores the essential considerations for selecting a computer and the principles of ergonomic design for a healthy workspace. ### 4.1 Factors for choosing a computer When purchasing a computer, several key factors need to be considered to ensure it meets your specific needs. These include usability, price, operating system, processor, RAM, storage, and brand [50](#page=50) [51](#page=51). #### 4.1.1 Usability and purpose Before buying, it's crucial to ask yourself why you need a computer and how much you intend to use it. This self-assessment will guide your decisions regarding other specifications [50](#page=50). #### 4.1.2 Price The cost of a computer is a significant determinant in the selection process, influencing the type and specifications of the device you can afford [50](#page=50). #### 4.1.3 Operating system The operating system (OS) is a fundamental software component. Different editions of an OS, such as Windows 10 Home, Pro, Enterprise, and Education, offer varying features and associated costs [50](#page=50). #### 4.1.4 Processor The processor is a critical component that directly impacts computer performance. Choosing a processor with high speed is essential for optimal performance [51](#page=51). #### 4.1.5 Random Access Memory (RAM) RAM determines how smoothly your computer operates and how many applications you can run concurrently. More RAM generally leads to smoother performance and the ability to multitask more effectively [51](#page=51). #### 4.1.6 Storage If you plan to save numerous large files, such as photos or videos, a high-capacity hard disk drive (HDD) is recommended. While Solid State Drives (SSDs) offer faster speeds than traditional HDDs, they are typically more expensive [51](#page=51). #### 4.1.7 Brand Reputable brands often lead the market due to their general market presence and sometimes attractive offers, including warranties and bundled software [52](#page=52). > **Example:** A minimum specification for a personal computer might include an Intel Core i7 CPU running at 4.90 GHz, 8 GB of RAM, Windows 10 Home, 2 GB of video memory, and a 1 TB hard disk [52](#page=52). ### 4.2 Ergonomics Ergonomics is the science of designing jobs, equipment, and workspaces to fit the worker. Its primary goal is to prevent Repetitive Strain Injuries (RSI), which can develop over time and potentially lead to permanent disability [53](#page=53). #### 4.2.1 Correct posture and workstation setup Achieving correct posture and setting up your workstation ergonomically is crucial for preventing strain and promoting comfort. Key principles include: * **Monitor placement:** Position your monitor directly in front of you, with the top of the screen at eye level. Maintain an arm's length distance from the monitor [54](#page=54). * **Shoulder posture:** Keep your shoulders relaxed and back, avoiding slouching or raising them [54](#page=54). * **Back support:** Ensure your back is straight and supported, ideally with the back of your chair reclined to a 100-110 degree angle [54](#page=54). * **Arm and wrist position:** Keep your arms bent in an L-shape, with elbows by your sides and wrists in a comfortable, neutral position [54](#page=54). * **Seating posture:** Sit straight with your hips far back in your chair. Adjust your chair as needed [54](#page=54). * **Keyboard position:** Place your keyboard close and directly in front of you. Leave a gap of four to six inches at the front of your desk to rest your wrists between typing spells [54](#page=54). * **Foot position:** Ensure your feet are flat on the floor, with your knees aligned with your hips [54](#page=54). --- ## Common mistakes to avoid - Review all topics thoroughly before exams - Pay attention to formulas and key definitions - Practice with examples provided in each section - Don't memorize without understanding the underlying concepts

| Term | Definition | |------|------------| | Computer | An electronic machine that accepts data, stores it, and processes it according to instructions (programs) to produce results (information). | | Data | Raw, unorganized facts that need to be processed to become meaningful. | | Information | Processed, organized, and structured data that is presented in a context to make it useful and understandable to humans. | | System Unit | A case that contains the essential components of a computer, including the motherboard, central processing unit (CPU), and random access memory (RAM). | | Monitor | An output device that displays graphical or text output, presenting information in a human-readable format. | | Keyboard | An input device used to input text, characters, and commands into a computer by pressing buttons called keys. | | Mouse | An input device used to point to objects on the screen, click on them, and move them, facilitating interaction with the computer interface. | | Desktop Computer | A personal computer designed to be placed on a desk, typically consisting of a separate system unit, keyboard, mouse, and monitor. | | Laptop Computer | A portable computer with an integrated screen and keyboard, powered by a battery, offering greater portability than a desktop. | | Tablet Computer | A handheld computer that is more portable than a laptop, utilizing a touch-sensitive screen for typing and navigation instead of a physical keyboard and mouse. | | Smartphone | A mobile phone with advanced computing capabilities, featuring a touch-sensitive screen and functions beyond traditional calling. | | Server | A software or hardware device that accepts and responds to requests made over a network, providing resources or services to clients. | | Mainframe Computer | A very large and expensive computer capable of supporting hundreds or thousands of users simultaneously, used for large-scale data processing. | | Supercomputer | The fastest and most powerful type of computer, used for highly specialized applications requiring immense computational power, such as complex mathematical calculations. | | Hardware | The physical components of a computer system that can be touched, including input devices, output devices, the CPU, motherboard, RAM, and storage devices. | | Motherboard | The main circuit board of a computer, serving as the central hub where most components and peripheral devices are connected. | | Central Processing Unit (CPU) | The brain of the computer; it is the central component responsible for executing instructions and performing calculations. | | Processor Speed | The speed at which the CPU can execute instructions, typically measured in Hertz (Hz), Megahertz (MHz), or Gigahertz (GHz). | | Arithmetic Logic Unit (ALU) | A part of the CPU that performs arithmetic operations (addition, subtraction, multiplication, division) and logic operations (comparisons). | | Control Unit (CU) | A component of the CPU that directs and coordinates the operations of the computer, managing the flow of instructions and data. | | Register | Temporary storage areas within the computer processor used to hold data and instructions that are currently being processed. | | Machine Cycle | The sequence of operations (fetching, decoding, executing, storing) that the CPU repeats to execute a single instruction. | | Primary Memory | Also known as main memory, it is where the operating system and applications are loaded for quick access by the CPU. It is volatile. | | RAM (Random Access Memory) | A type of primary memory that is volatile, meaning its contents are lost when the power is switched off. It is used to store data and instructions for currently running applications. | | ROM (Read-Only Memory) | A type of non-volatile memory whose contents are permanent and cannot be easily changed. It typically stores essential boot-up instructions for the computer. | | Input Device | A piece of computer hardware used to provide data and send instructions to the computer. | | Output Device | A piece of computer hardware used to communicate the results of data processing to the user. | | Secondary Memory | Also known as storage devices, these are non-volatile and persistent, used for long-term storage of data and information. They are not directly accessed by the processor. | | Hard Disk Drive (HDD) | A main, large data storage device that uses magnetic disks to store the operating system, applications, and user data. | | Solid State Drive (SSD) | A storage device that uses non-volatile flash memory chips to store data, offering faster performance than HDDs. | | Compact Disc (CD) | A common type of removable optical media used for storing music and data. | | Digital Versatile Disc (DVD) | A popular type of removable optical media with the same dimensions as a CD but with higher storage capacity, often used for digital video. | | Blu-ray Disc (BD) Drive | A digital optical disc storage media capable of storing high-definition and ultra-high-definition video. | | USB Flash Drive | A portable flash memory storage device integrated with a USB connector, typically small, lightweight, removable, and rewritable. | | External Hard Disk | An external storage device that connects to a computer, usually via USB, offering additional storage capacity. | | Bit | The smallest unit of data in a computer, representing a single binary value of either 0 or 1. | | Byte | A unit of data consisting of eight bits, commonly used to represent a single character. | | Kilobyte (KB) | A unit of digital information equal to 1,024 bytes. | | Megabyte (MB) | A unit of digital information equal to 1,024 kilobytes. | | Gigabyte (GB) | A unit of digital information equal to 1,024 megabytes. | | Terabyte (TB) | A unit of digital information equal to 1,024 gigabytes. | | Software | A set of instructions (programs) that tells a computer what to do and how to do it. | | System Software | Programs that automatically load when a computer starts up and control or maintain its operations and devices. This includes operating systems and utility software. | | Application Software | Programs designed to make users more productive and assist them with specific personal or professional tasks. | | Operating System (OS) | System software that manages computer hardware and software resources and provides common services for computer programs. | | Utilities Software | A type of system software that adds functionality to a computer or helps it perform better, such as antivirus or disk repair tools. | | Device Driver | A type of system software designed to enable interaction between a hardware device and the operating system or programs that use it. | | Software Copyright | Legal protection granted to software creators, preventing unauthorized copying, distribution, and modification of their work. | | End-User License Agreement (EULA) | A legal contract between the software manufacturer and the end user, detailing how the software can and cannot be used and any imposed restrictions. | | Shareware | Proprietary software provided to users on a trial basis without initial payment; a license must be purchased for continued use after the trial period. | | Freeware | Software that is fully functional for an unlimited time at no cost, though the author usually restricts rights to copy, distribute, or create derivative works. | | Proprietary Software | Software that is copyrighted and has limits on its use, distribution, and modification, imposed by its publisher, vendor, or developer. | | Open-Source Software | Software developed collaboratively and distributed with licenses that grant rights to use, modify, and share it in both modified and unmodified forms. | | Usability | A measure of how easy a computer system is to use, considering factors like the user interface and the intuitiveness of its operation. | | Price | The cost of a computer system, which is a significant factor influencing purchasing decisions. | | Processor | A critical computer component responsible for executing instructions and performing calculations; a faster processor generally leads to better computer performance. | | Random Access Memory (RAM) | The amount of RAM in a computer; more RAM allows for smoother performance and the ability to run more applications simultaneously. | | Storage | The capacity of a computer to store files and data; high-capacity storage is important for users who save large files like photos or videos. | | Brand | The manufacturer of a computer, with well-known brands often favored for their reputation, reliability, and included offers like warranties. | | Ergonomics | The science of designing jobs, equipment, and workplaces to fit the worker, aimed at preventing repetitive strain injuries and improving overall well-being. | | Repetitive Strain Injury (RSI) | Injuries that can develop over time due to repetitive movements or poor posture while using equipment, potentially leading to long-term disability. |