RAM is called volatile memory because when the power goes off, the contents of RAM get erased.
Random Access Memory(RAM) may be classified as Dynamic and static.
Dynamic RAM consists of a transistor and capacitor that is capable of storing an electric charge.
Since the charge on capacitors tends to leak off, provision is made to periodically refresh the storage charge.
Thus dynamic RAM provides volatile storage.
Static RAM is also volatile but as long as they are supplied with power, they need no special regenerator circuits to retain the stored data.
Static RAM consists of filp flops.
A flip flop is a binary cell capable of storing one of information.