Operating System Explained



The Operating System (OS) is a special computer program that is essential to the efficient running and organization of all the other programs within the computer.

The operating system (OS) carries out tasks, instructions and controls which operations within the computer are carried out and in which order. OS have direct control and access to your computer hardware and memory locations . They perform input / output operations on various memory locations and control the hardware that make the application software do a task. Some common operating systems are

  1. Microsoft Windows
  2. Linux
  3. Unix
  4. Mac OSX
  5. DOS
  6. Assembler and Compiler Software

When the computer is switched on it carries out a Power On Self Test (POST) and boot-up entirely on its own because the necessary software is in ROM memory. This process ensures that all the hardware components are running and that the CPU and memory are functioning correctly. A series of beeps denotes any detected errors.

The second function of the boot-up operation is to search drives for an operating system and then launch it, by reading the operating system files and copying them to the RAM. The operating system is not part of the PC and needs to be located at each boot-up, this makes upgrading or fixing errors in the OS much simpler and allows a choice of operating systems.

Examples of Operating Systems operations:

    External
  1. booting
  2. user login
  3. Double-click an icon to launch an application
  4. Read and write data to files
  5. Connecting to or disconnection from the internet.

    Internal
  6. Memory management (How RAM is used by whom)
  7. Process management (How a process (a running program, for example) are controlled)
  8. Resource management.

A Graphical User Interface (GUI) is a way of showing the computer's facilities using icons (pictures) and menus (names). Instead of typing a technical instruction the mouse is used to click on an icon (picture) or menu (names) to select or perform an action.