Computer Hardware

Input Devices

When data is entered into the computer system, it is called an input. Input comes in various forms; texts, graphics, audio and video. Input devices are needed to input data into the computer system.

Keyboard, mouse, scanner, barcode reader and digital camera are some example of input devices.

Output

Output is data that has been processed into a useful form, called information. There are four types of output, which are texts, graphics, audio and video.

The text consists of characters that are used to create texts, sentences and paragraphs.

Graphics are digital representations of non text information such as drawings, charts and photographs.

Audio is music, speech or any other sound. Video consists of images that provide the appearance of full motion

Output Devices

Output is the result of raw input data that has been processed by the central processing unit into meaningful information. Common forms of output are texts, numbers, graphics, sounds, animations and videos.The most common output devices are computer screens, speakers and printers.

Storage Device

The system’s primary storage, Random Access Memory (RAM) can only hold data temporarily. Thus, secondary storage is needed to provide additional storage. The data stored in the secondary storage is considered permanent until it is deleted or removed.

Secondary storage can be magnetic disks and optical disks. Examples of secondary storage are hard disks, rewritable CDs and DVDs as well as removable disks such as pen drives

Peripheral Device
External hardware devices attached to the computer are called peripheral equipments

CPU

The central processing unit or the CPU is the brain of the computer.

All processing activities are done in the CPU. It utilises the computer memory to execute instructions from the application software and accomplish a task. For example: editing a letter, drawing a picture and sorting numbers.

The processor must be connected to input devices, output devices and storage devices to carry out the above mentioned tasks.

Input

Input is any data or instructions that we enter into the computer system for processing.

There are some common ways of feeding input data into the system, which are:

• typing on a keyboard

• pointing with a mouse

CPU accepts instruction from the user and translates the instruction into readable information (decode).

Process

The processing unit controls all activities within the system. For every instruction, the control unit repeats a set of four basic operations called the machine cycle

Storage

Storage is a location which data, instruction and information are held for future use. Every computer uses storage to hold system software and application software.

When we issue a command to start the application software, the operating system locates the program in storage and loads it into memory.

A storage medium, also called secondary storage is the physical material in the computer that keeps data, instruction and information.

A storage device is the computer hardware that records or retrieves items to and from storage media.

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