Operating systems

An operating system (OS) is software that is loaded by the computer after boot-up. The operating system:

  • controls the operations of the hardware in a computer system
  • manages all other software

What is provided by the OS depends on the purpose of the individual device.

For example, the OS on your phone will perform different tasks (providing a graphical user interface) compared to the OS found in the embedded system of a typical car (controlling fuel consumption). Examples of operating systems are iOS, Windows and Android.

Operating system software

The role of the OS is to control the hardware and software to ensure all parts of the computer can work together. It also provides us with the ability to interact with the computer.

Memory allocation

Memory management: the OS keeps track of every memory location and is responsible for making memory available for different processes, such as allocating free space in memory to programs. The OS also deals with virtual memory and swapping pages in and out of RAM.


File management: the OS is responsible for organising and keeping track of files in a computer system. It organises where and how files are stored, found, read and deleted. The file management system of an OS can:

  • find existing files
  • allocate space to new files
  • keep track of all available space

It is the file management system that allows us to see data held on secondary storage devices, such as external hard drives using programs like File Explorer on Windows or Finder on OSX. File management programs provide a graphical user interface for accessing file systems.