Computers

A computer is a machine (Öffnet in neuem Fenster) that can be programmed to carry out (Öffnet in neuem Fenster) sequences of arithmetic (Öffnet in neuem Fenster) or logical operations (Öffnet in neuem Fenster) (computation (Öffnet in neuem Fenster)) automatically. Modern digital electronic (Öffnet in neuem Fenster) computers can perform generic sets of operations known as programs (Öffnet in neuem Fenster). These programs enable computers to perform a wide range of tasks. A computer system is a nominally complete computer that includes the hardware (Öffnet in neuem Fenster), operating system (Öffnet in neuem Fenster) (main software (Öffnet in neuem Fenster)), and peripheral (Öffnet in neuem Fenster) 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 (Öffnet in neuem Fenster) or computer cluster (Öffnet in neuem Fenster).

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

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

Conventionally, a modern computer consists of at least one processing element (Öffnet in neuem Fenster), typically a central processing unit (Öffnet in neuem Fenster) (CPU) in the form of a microprocessor, along with some type of computer memory (Öffnet in neuem Fenster), typically semiconductor memory (Öffnet in neuem Fenster) 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 (Öffnet in neuem Fenster). Peripheral devices include input devices (keyboards, mice, joystick (Öffnet in neuem Fenster), etc.), output devices (monitor screens, printers (Öffnet in neuem Fenster), etc.), and input/output devices that perform both functions (e.g., the 2000s-era touchscreen (Öffnet in neuem Fenster)). Peripheral devices allow information to be retrieved from an external source and they enable the result of operations to be saved and retrieved.

Etymology