Computers

A computer is a machine (Si apre in una nuova finestra) that can be programmed to carry out (Si apre in una nuova finestra) sequences of arithmetic (Si apre in una nuova finestra) or logical operations (Si apre in una nuova finestra) (computation (Si apre in una nuova finestra)) automatically. Modern digital electronic (Si apre in una nuova finestra) computers can perform generic sets of operations known as programs (Si apre in una nuova finestra). These programs enable computers to perform a wide range of tasks. A computer system is a nominally complete computer that includes the hardware (Si apre in una nuova finestra), operating system (Si apre in una nuova finestra) (main software (Si apre in una nuova finestra)), and peripheral (Si apre in una nuova finestra) equipment needed and used for full operation. This term may also refer to a group of computers that are linked and function together, such as a computer network (Si apre in una nuova finestra) or computer cluster (Si apre in una nuova finestra).

A broad range of industrial (Si apre in una nuova finestra) and consumer products (Si apre in una nuova finestra) use computers as control systems (Si apre in una nuova finestra). Simple special-purpose devices like microwave ovens (Si apre in una nuova finestra) and remote controls (Si apre in una nuova finestra) are included, as are factory devices like industrial robots (Si apre in una nuova finestra) and computer-aided design (Si apre in una nuova finestra), as well as general-purpose devices like personal computers (Si apre in una nuova finestra) and mobile devices (Si apre in una nuova finestra) like smartphones (Si apre in una nuova finestra). Computers power the Internet (Si apre in una nuova finestra), which links billions of other computers and users.

Early computers were meant to be used only for calculations. Simple manual instruments like the abacus (Si apre in una nuova finestra) have aided people in doing calculations since ancient times. Early in the Industrial Revolution (Si apre in una nuova finestra), some mechanical devices were built to automate long, tedious tasks, such as guiding patterns for looms (Si apre in una nuova finestra). More sophisticated electrical machines did specialized analog (Si apre in una nuova finestra) calculations in the early 20th century. The first digital (Si apre in una nuova finestra) electronic calculating machines were developed during World War II (Si apre in una nuova finestra). The first semiconductor (Si apre in una nuova finestra) transistors (Si apre in una nuova finestra) in the late 1940s were followed by the silicon (Si apre in una nuova finestra)-based MOSFET (Si apre in una nuova finestra) (MOS transistor) and monolithic integrated circuit (Si apre in una nuova finestra) chip technologies in the late 1950s, leading to the microprocessor (Si apre in una nuova finestra) and the microcomputer revolution (Si apre in una nuova finestra) in the 1970s. The speed, power and versatility of computers have been increasing dramatically ever since then, with transistor counts (Si apre in una nuova finestra) increasing at a rapid pace (as predicted by Moore's law (Si apre in una nuova finestra)), leading to the Digital Revolution (Si apre in una nuova finestra) during the late 20th to early 21st centuries.

Conventionally, a modern computer consists of at least one processing element (Si apre in una nuova finestra), typically a central processing unit (Si apre in una nuova finestra) (CPU) in the form of a microprocessor, along with some type of computer memory (Si apre in una nuova finestra), typically semiconductor memory (Si apre in una nuova finestra) chips. The processing element carries out arithmetic and logical operations, and a sequencing and control unit can change the order of operations in response to stored information (Si apre in una nuova finestra). Peripheral devices include input devices (keyboards, mice, joystick (Si apre in una nuova finestra), etc.), output devices (monitor screens, printers (Si apre in una nuova finestra), etc.), and input/output devices that perform both functions (e.g., the 2000s-era touchscreen (Si apre in una nuova finestra)). Peripheral devices allow information to be retrieved from an external source and they enable the result of operations to be saved and retrieved.

Etymology