An operating system is usually defined as a set of programs which permit the continuous operation of a computer. The software controls scheduling and execution of application programs and use of computer resources. Simplistically, the operating system acts as the interface between the application program, the user and the IT hardware. The security and control of an operating system is a complex issue and provides an area of potentially major risk to an organisation. The complexity, size and functionality of operating systems varies enormously from one manufacturer to another. Some operating systems may include functionality, such as database management systems and security software, whilst others will require separate systems software.
