3. CPUThe Central Processing Unit (CPU) or processor is the portion of a computer system that carries out the instructions of a computer program, and is the primary element carrying out the computer's functions.
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5. Memory Computer data storage, often called storage or memory, refers to computercomponents, devices, and recording mediathat retain digital dataused for computing for some interval of time.
6. Computer data storage provides one of the core functions of the modern computer. It is one of the fundamental components of all modern computers, and coupled with a central processing unit(CPU, a processor), implements the basic computer model used since the 1940s.
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8. RAM Random-access memory (usually known by its acronym, RAM) is a form of computer data storage. Today, it takes the form of integrated circuits that allow stored data to be accessed in any order (i.e., at random).
9. The word RAM is often associated with volatile types of memory (such as DRAM memory modules), where the information is lost after the power is switched off.
17. Peripheral (device) A peripheral is a device attached to a host computer but not part of it whose primary functionality.
18. Examples are printers, scanners, microphones, webcams, cameras ,TV card ,joypad ,joystick , usb device,reader ZIP, …
19. Input peripheral An input device is any peripheral (piece of computer hardware equipment) used to provide data and control signals to an information processing system (such as a computer).
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21. Keyboard A 'keyboard' is a human interface device which is represented as a layout of buttons. Each button, or key, can be used to either input a linguistic character to a computer.
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23. Pointing A pointing device is any human interface device that allows a user to input spatial data to a computer. In the case of mice and touch screens, this is usually achieved by detecting movement across a physical surface.
24. Scanner In computing, a scanner is a device that optically scans images, printed text, handwriting, or an object, and converts it to a digital image.1-Scanner 3 dimensions2-scanner 2 dimensionsgive the difference between 1 and 2
26. Image scanner, which digitizes a two-dimensional image. 3D scanner, which digitizes the three-dimensional shape of a real object .
27. Output devicesAn output device is any piece of computer hardware equipment used to communicate the results of data processing carried out by an information processing system (such as a computer) to the outside world.