When the word computer is heard we at once think of the desk top PC left on the desk at home or in your office. True that it is the PC we call a computer but these electronic brains are embedded in many instruments in day to day use from toy cars to fighter jets.
The earliest computers were made in the mid 19th century. The were very large sometimes filling a room the size your of your bed room. These were improved and with the advent of digital technology they improved vastly and reached the present day state.
Basically to complete a computer there are two things which should work together. They are hard ware and software. Hardware is the physical instruments you can see while software are the programs running inside the machine making it to work. In a basic computer there are three parts in the hardware. They are the input device the output device and the central processing unit. The basic input devices are the key board and the mouse. The basic output device is the monitor. The central processing unit is the real computer which does the calculation and execution of programs.
Software too has two sets. One is the operating system which makes the connection between the hardware and the programs. The other programs are the various programs used by the computer they could be word processers, spread sheets, programming software and so on.
Though the above is the basic PC presently it has developed into various branches. While basic computer has evolved into smaller laptops note books and net books the microcomputers are embedded in many instruments like the toys, games and industrial robots.
The computer is keeping on developing and soon we might be able to see a car being driven by one of these. Still the PC at home left on your desk is your faithful friend.