- An Operating system (OS) is a basic software that makes the computer to work.
- When a computer is switched on, there is no information in its RAM.
- At the same time, in ROM, the pre-written program called POST (Power on Self Test) will be executed first.
- This program checks if the devices like RAM, keyboard, etc., are connected properly and ready to operate.
- If these devices are ready, then the BIOS (Basic Input Output System) gets executed.
- This process is called Booting.
- Thereafter, a program called “Bootstrap Loader” transfers OS from hard disk into main memory.
- Now the OS gets loaded (Windows/Linux, etc.,) and will get executed.
Booting process is of two types.
- Cold Booting
- Warm Booting
Cold Booting:
- When the system starts from initial state i.e. it is switched on, we call it cold booting or Hard Booting.
- When the user presses the Power button, the instructions are read from the ROM to initiate the booting process.
Warm Booting:
- When the system restarts or when Reset button is pressed, we call it Warm Booting or Soft Booting.
- The system does not start from initial state and so all diagnostic tests need not be carried out in this case.
- There are chances of data loss and system damage as the data might not have been stored properly.