Booting is the process that the system undergo before it is ready to be used for any specific task i.e the process of starting the computer system and loading the operating system.

Types of booting

 The two types of booting are cold booting and warm booting.

Cold booting: 

Cold Booting is a startup process that begins with turning on the computer’s power. Typically, a cold boot involves some basic hardware checking by the system followed by loading of the operating system from disk into memory.

Warm booting:  

Warm Booting is a system restart that does not involve turning on the power and waiting for the computer to check itself and its devices. A warm boot typically means loading or reloading the computer’s operating system.                                                             
On IBM and compatible personal computers, a warm boot is accomplished by using the Ctrl-Alt-Del key sequence.
On Apple Macintosh computers, a warm boot can be requested with the Restart command on the Special menu.