A computer is a digital electronic machine that can be programmed to automatically perform arithmetic or logical operations (computation). Programs are generic sets of operations that modern computers can perform.
These programs allow computers to perform a variety of tasks. A computer system is a “complete” computer that includes the necessary hardware, operating system (main software), and peripheral equipment for “full” operation.
This term can also refer to a collection of computers that are linked and work together, such as a computer network or a computer cluster.
Computers are used as control systems in a wide range of industrial and consumer products.
Simple special-purpose devices such as microwave ovens and remote controls, as well as factory devices such as industrial robots and computer-aided design, are included, as are general-purpose devices such as personal computers and mobile devices such as smartphones. The Internet is powered by computers, which connects billions of other computers and users.
Early computers were only intended to be used for calculations. Since ancient times, simple manual instruments such as the abacus have aided people in performing calculations.
Some mechanical devices were created early in the Industrial Revolution to automate long, tedious tasks, such as guiding patterns for looms. In the early twentieth century, more sophisticated electrical machines performed specialized analog calculations.
During World War II, the first digital electronic calculating machines were developed.
The late 1940s saw the introduction of the first semiconductor transistors, which were quickly followed by silicon-based MOSFET (MOS transistor) and monolithic integrated circuit (IC) chip technologies in the late 1950s, paving the way for the microprocessor and microcomputer revolution in the 1970s.
Since then, computer speed, power, and versatility have increased dramatically, with transistor counts increasing at a rapid pace (as predicted by Moore’s law), increasing in the Digital Revolution in the late twentieth to early twenty-first centuries.
A modern computer typically includes at least one processing element, typically a central processing unit (CPU) in the form of a microprocessor, as well as some type of computer memory, most commonly semiconductor memory chips.
The processing element performs arithmetic and logical operations, and a sequencing and control unit can alter the order of operations based on stored data.
Input devices (keyboards, mice, joysticks, and so on) and output devices (monitor screens, printers, and so on) are examples of peripheral devices, as are input/output devices that perform both functions (e.g., the 2000s-era touchscreen).
Peripheral devices enable the retrieval of information from an external source as well as the saving and retrieval of operation results.