COMPUTER
A computer is a machine for manipulating data according to a list of instructions.
Computers take numerous physical forms. Early electronic computers were the size of a large room, consuming as much power as several hundred modern personal computers. Today, computers can be made small enough to fit into a wrist watch and be powered from a watch battery . Society has come to recognize personal computers and their portable equivalent, the laptop computer , as icons of the information age ; they are what most people think of as "a computer". However, the most common form of computer in use today is by far the embedded computer . Embedded computers are small, simple devices that are often used to control other devices—for example, they may be found in machines ranging from fighter aircraft to industrial robots , digital cameras , and even children's toys
The ability to store and execute programs makes computers extremely versatile and distinguishes them from calculators . The Church–Turing thesis is a mathematical statement of this versatility: Any computer with a certain minimum capability is, in principle, capable of performing the same tasks that any other computer can perform. Therefore, computers with capability and complexity ranging from that of a personal digital assistant to a supercomputer are all able to perform the same computational tasks as long as time and storage capacity are not considerations
