Function of OS

Function of OS

1. Multi-tasking/Process Management

   • Most systems commonly have several programs loaded into memory at the same time.
   • The operating system will also be running lots of background tasks just to manage the computer itself.
   • A processor can only execute one instruction at a time (assuming it only has one core).
   • The operating system has to mange all the programs running to make sure each one gets enough processor time.

2. User interface

   • Operating systems need to provide a means of communicating with them.
   • This means making it possible for the user to issue commands
   • The user interface is the way in which users interact with computer hardware.
   • an be either Graphical (GUI) or Command Line.

3. Memory Management

   • When a program is running it must be in the computer’s main memory (RAM). The main memory has a finite size.
   • The operating system must manage where in memory the programs will go.
   • The operating system tracks where programs and data are at any time to make efficient use of the space in memory and to make sure nothing gets overwritten by something else.
   • As a program is finished it can be removed from memory and as as new ones are run they will be loaded into memory.

4. Peripheral management

   • Peripherals are any computer hardware components that are not part of the CPU i.e. Input, Output or Storage devices.
   • A function of the operating system is to manage these devices.
   • The operating system may need to find / ask user to install suitable drivers for the device to work.
   • These drivers allows an operating system to communicate with the device.

5. Security

   • Operating systems usually allow the authentication of users, i.e. they can be set up to check that users are who they say they are.
   • This normally involves users having user ids and password.
   • Operating systems also handle file privileges, these are right assigned to users and group.
   • This control who can read / write and execute files.