ETYM Latin: cf. French calculateur.
Broadly, any device that performs arithmetic operations on numbers. Sophisticated calculators can be programmed for certain functions and can store values in memory, but they differ from computers in several ways: they have a fixed set of commands, they do not recognize text, they cannot retrieve values stored in a data file, and they cannot find and use values generated by a program such as a spreadsheet.
Pocket-sized electronic computing device for performing numerical calculations. It can add, subtract, multiply, and divide; many calculators also compute squares and roots and have advanced trigonometric and statistical functions. Input is by a small keyboard and results are shown on a one-line computer screen, typically a liquid-crystal display (LCD) or a light-emitting diode (LED). The first electronic calculator was manufactured by the Bell Punch Company in the US 1963.
1. A small machine for mathematical calculations; SYN. calculating machine.
2. An expert at calculation (or at operating calculating machines); SYN. reckoner, figurer, estimator, computer. + prikaži više

A machine for performing calculations automatically; SYN. data processor, electronic computer, information processing system.
Any device capable of processing information to produce a desired result. No matter how large or small they are, computers typically perform their work in three well-defined steps: (1) accepting input, (2) processing the input according to predefined rules (programs), and (3) producing output. There are several ways to categorize computers, including class (ranging from microcomputers to supercomputers), generation (first through fifth generation), and mode of processing (analog versus digital). See the table. See also analog, digital (definition 2), integrated circuit, large-scale integration, very-large-scale integration.
Programmable electronic device that processes data and performs calculations and other symbol-manipulation tasks. There are three types: the digital computer, which manipulates information coded as binary numbers (see binary number system); the analog computer, which works with continuously varying quantities; and the hybrid computer, which has characteristics of both analog and digital computers.
There are four types of digital computer, corresponding roughly to their size and intended use. Microcomputers are the smallest and most common, used in small businesses, at home, and in schools. They are usually single-user machines. Minicomputers are found in medium-sized businesses and university departments. They may support from 10 to 200 or so users at once. Mainframes, which can often service several hundred users simultaneously, are found in large organizations, such as national companies and government departments. Supercomputers are mostly used for highly complex scientific tasks, such as analyzing the results of nuclear physics experiments and weather forecasting.
Microcomputers now come in a range of sizes from battery-powered pocket PCs and electronic organizers, notebook and laptop PCs to floor-standing tower systems that may serve local area networks or work as minicomputers. Indeed, most minicomputers are now built using low-cost microprocessors, and large-scale computers built out of multiple microprocessors are starting to challenge traditional mainframe and supercomputer designs.
history
Computers are only one of the many kinds of computing device. The first mechanical computer was conceived by Charles Babbage 1835, but it never went beyond the design stage. In 1943, more than a century later, Thomas Flowers built Colossus, the first electronic computer. Working with him at the time was Alan Turing, a mathematician who seven years earlier had published a paper on the theory of computing machines that had a major impact on subsequent developments. John von Neumann's computer, EDVAC, built 1949, was the first to use binary arithmetic and to store its operating instructions internally. This design still forms the basis of today's computers.
basic components
At the heart of a computer is the central processing unit (CPU), which performs all the computations. This is supported by memory, which holds the current program and data, and “logic arrays”, which help move information around the system. A main power supply is needed and, for a mainframe or minicomputer, a cooling system. The computer’s “device driver” circuits control the peripheral devices that can be attached. These will normally be keyboards and VDTs (visual display units) for user input and output, disc drive units for mass memory storage, and printers for printed output. + prikaži više