2. Volatile Memory

How many times have you worked for ages on something and just before you were about to save it the computer crashed or your mate 'accidentally' switched it off? And as most of you have probably experienced, when you reboot your computer, all of that work is gone forever.

The reason for this is that anything you are currently working on is stored in main memory. Main memory is almost always volatile, with the exception of ROM chips, which will be discussed later.

Volatile memory is cleared whenever the supply of power is lost. In contrast, non-volatile memory will continue to hold anything it was storing even if it is not receiving any power.

Secondary storage is always non-volatile, as the programs and data that are held there are meant to be kept long-term. This is why, while you might lose any files you are working on if power is cut, if you save them first those files are safe.

Volatile memory includes RAM, CPU registers and the cache.

KEY TERM: Volatile memory is a type of memory that loses its data once power to the memory chip is switched off or interrupted.