There are four basic functions of Computer system . They are as follows :
• Data processing
• Data storage
• Data movement
Data processing: The computer must be able to process data.The data may take a wide variety of forms, and the range of processing requirements is broad.
Data storage: It is also essential that a computer store data. Even if the computer is processing data on the fly (i.e., data come in and get processed, and the results go out immediately), the computer must temporarily store at least those pieces of data that are being worked on at any given moment.Thus, there is at least a short-term data storage function.
Equally important, the computer performs a long-term data storage function. Files of data are stored on the computer for subsequent retrieval and update.
Data movement : The computer must be able to move data between itself and the outside world. The computer’s operating environment consists of devices that serve as either sources or destinations of data.When data are received from or delivered to a device that is directly connected to the computer, the process is known as input–output (I/O), and the device is referred to as a peripheral. When data are moved over longer distances, to or from a remote device, the process is known as data communications.
Control : Finally, there must be control of these three functions. Ultimately, this control is exercised by the individual(s) who provides the computer with instructions.Within the computer, a control unit manages the computer’s resources and orchestrates the performance of its functional parts in response to those instructions.