Core Components of a Computer System | Basic Computer Course for SSC | Computer Education for All

Core Components of a Computer System A computer system comprises several core components that work together to perform various tasks. 1.3.1 Input Devices Input devices are used to provide data into the computer system. Keyboard It is the main input device to communicate with the computer. It allows the computer user to enter letters, numbers, and special symbols into the computer. POINT TO PONDER: Why the keys on keyboard are not arranged in alphabetical order? Mouse It is a hand-held device used to control the movement of cursor or pointer on the screen. It has two or three buttons at the front that allows the computer user to make selection in menu, draw graphics or open files, folders and programs. Microphone It is a device that allows computer user to input audio into the computer. It changes audio signals into electrical signals which are translated into digital form by the sound card for processing in the computer. Scanner It is a device that captures images from photographs, magazines, books etc. and stores them in computer in digital form. Barcode Reader It is a device that reads the barcode printed on products that represents product code, description and price. Digital Camera It is input/output device used to capture pictures and store them in digital form. Touch Screen It is a pressure-sensitive display screen that is used to interact with the computer by touching pictures or words with finger. 1.3.2 System Unit System unit is the main part of computer. It includes motherboard, power supply and drives (such as DVD and hard disk) inside the computer casing. All the input/output devices of a computer are connected to system unit through the ports. Motherboard Motherboard is the main circuit board inside the system unit. It contains microprocessor, main memory, expansion cards, many IC chips, connectors, and other electronic components. Microprocessor A microprocessor is the main chip on the motherboard that controls all the activities of the computer. It is also known as Central Processing Unit (CPU) or simply processor. ALU is the part of the computer that performs all the calculations and comparisons. It consists of arithmetic unit and logic unit. Arithmetic unit performs all the arithmetic operations such as addition, subtraction, multiplication, and division. Logic unit performs logical operations which include comparisons of numbers or alphabets. Control unit controls the operations of all the components of the computer. It controls the working of all the input/output devices, storage devices and ALU. CU loads programs into memory and executes them. It consists of very complicated circuits. Registers are small memory units inside the microprocessor used to temporarily store some information during the execution of a program. Some commonly used registers are Instruction Register, Accumulator Register, Data Register and Memory Address Register. 1.3.3 Storage Devices Storage devices are used to store programs and data that are not currently used by the computer. They have huge storage capacity. Therefore, they are also known as mass storage devices or secondary memory. Hard Disk A hard disk is a magnetic storage device used to store computer data permanently. Compact Disk (CD) CD (DVD) is a portable optical storage device with a storage capacity of 700 Megabytes (MB). Digital Versatile Disk DVD is also portable optical storage device. It has the same thickness and diameter as CD but has more storage capacity. Memory Card Memory card is a small storage device having storage capacity of few Gigabytes. USB Flash Drive USB flash drive is a small portable drive that is connected to the computer through a USB port. 1.3.4 Output Devices Output devices are used to display text, graphics, and images on the monitor or to print information on paper. Monitor It is an output device that has a screen on which information is displayed. It has two common types i.e. CRT (Cathode Ray Tube) monitor and LED (Light Emitting Diode) monitor. Printer A printer is an output device that prints text and graphics on paper which is known as hardcopy. There are two types of printers which are impact and non-impact printers. Impact printer Impact printer uses an electro-mechanical mechanism which causes the character shape to strike against the paper and leave an image of the character on the paper. Non-Impact printer Non-Impact printer prints without striking the paper. There are two types of non-impact printers which are inkjet and laser printers. Plotter The plotter is an output device used for printing engineering drawings, machine parts, building designs, maps, charts and panna-flexes, etc. Speaker A speaker is a device used to produce audio output. A pair of speakers are attached to the sound card on the motherboard. Please like, share, subscribe and comments for more Computer Education notes, exams tutorial and interview preparations of Information Technologies jobs.