If we take the example of the taxi, the car (vehicle) is the hardware, the driver is the Operating System, and the passenger is the Application Software. The Operating System, or OS, is an enabling mechanism. Operating systems control and manage software use through interaction with hardware and basic system operations. Early computers did not have an OS, and a human Operator was required to load and run programs. The OS has some core components called the kernel, and some other components which enable application software to run. These common core services include, but are not limited to: disk access, memory management, task scheduling, and access to other hardware devices. The exact delineation between an OS and application software is not clear. For example, in the famous anti-trust litigation against Microsoft, it was argued by the prosecutors that Internet Explorer did not form part of the OS, and so did not require to be bundled with the Windows OS.
Operating systems are huge software, sometimes software suite, that are vital software components within the computer system. Today, the OS contains many accessory software that allow us to play video, listen to music, see pictures, write on word processing software, and other memory and disk management tools.
Operating systems are usually designed for some specific computer architecture. They also target various computing platforms like the desktop, the mainframe and the server. Today even PDAs have their own OSes, like the Windows CE and the Palm OS. There can be Command Line Interface (CLI) OS like the DOS, or a Graphic User Interface (GUI) OS like the Windows. In the desktop category, Microsoft has virtual monopoly, although the Unix-based Linux has been getting wide acceptance.
In this section of directory, we provide links to vendors offering various operating systems, guides and other resources.