In computing, an input device is any peripheral used to provide data and control signals to an information processing system such as a computer or other information appliance. Examples of input devices include keyboards, mice, scanners, digital cameras and joysticks.
An output device is any piece of computer hardware equipment used to communicate the results of data processing carried out by an information processing system which converts the electronically generated information into human-readable form.
Computer data storage, often called storage or memory, is a technology consisting of computer components and recording media used to retain digital data. It is a core function and fundamental component of computers. The central processing unit (CPU) of a computer is what manipulates data by performing computations. In practice, almost all computers use a storage hierarchy, which puts fast but expensive and small storage options close to the CPU and slower but larger and cheaper options farther away. Often the fast, volatile technologies are referred to as "memory", while slower permanent technologies are referred to as "storage", but these terms can also be used interchangeably. The CPU consists of two main parts: control unit and arithmetic logic unit. The first controls the flow of data between the CPU and memory; the latter performs arithmetic and logical operations on data.