Operating system refers to the control and management of the entire computer system hardware and software resources, and reasonable organization scheduling computer work and resource allocation, in order to provide users and other software convenient interface and environment of the program set. An operating system, typically configured on computer hardware, has the following goals:

(1) Effectiveness (improve resource utilization; Improve system throughput)

(2) the convenience

(3) extensibility

(4) open

From a resource management perspective, operating systems have five basic functions,

(1) Process and thread management -- process thread state, control, synchronization mutually exclusive, communication scheduling, etc

(2) Storage management -- allocation/reclamation, address translation, storage protection, etc

(3) File management -- file directories, file operations, disk space, file access control

(4) Device management -- device drivers, distribution recycling, buffering technology, etc

(5) User interface -- system command and programming interface