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Input is the data that is fed to the computer by the user. Some examples of input are numbers for calculation,
marks of students of a class, etc.
Processing refers to the series of actions by which the computer converts raw data into information. The
processing of data is done by the CPU.
Output is the result which is termed as information. Some examples of output are graphs, mark sheets,
reports, animated movies, etc.
Components of a Computer System
A computer system functions with the help of ‘Hardware’ and ‘Software’. The physical components of a
computer system are known as ‘Hardware’. The virtual components are known as ‘Software’. It is abstract, i.e.,
it has no physical identity.
Hardware is the electro-mechanical part of a computer that is capable of computing and manipulating
information, whereas software is a collection of instructions or programs which directs and coordinates the
functions of computing and manipulating.
A computer is an instruction-driven device that accepts data, processes it and produces the desired results in
the form of information. Data are fed into the computer through the input devices which are then processed
inside a CPU and then results are displayed through the output devices. Thus, a computer system constitutes
input devices, output devices and a processing device.
Input Devices
There are various types of input devices. Some of the common input devices are keyboard, mouse, joystick,
scanner, OMR, OCR, MICR, light pen, bar code reader, microphone, digital camera, web camera, etc.
Keyboard
Keyboard is a standard input device. It is mainly used to type text and to send the instructions to a computer
with the help of keys. Keyboard keys are the buttons that represent alphabets, numerics, alphanumerics
and special characters. The keys can be used individually or in combination with other keys. The keyboard
normally contains 101 to 108 keys.
Depending on the position or placement of the keys, the layout of a keyboard comes in various styles such
as QWERTY, QWERTZ, AZERTY and DVORAK. QWERTY keyboard is the most commonly used keyboard. It
is based on the English language. Its name is derived from the sequence in which six alphabetical keys are
positioned on the upper line of the keyboard. AZERTY type keyboard is mostly used in France (‘A’ and ‘Z’
characters replace ‘Q’ and ‘W’ on such keyboards). QWERTZ type keyboard is widely used in Germany and
Central Europe.
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