Primary storage is also known as main memory, system memory or simply memory.

Memory is a temporal location where both data and instructions are held for immediate access and use during processing. Most primary storage is considered as volatile, meaning that both data and instructions are lost when the computer is powered off. Random access memory (RAM) is a form of primary storage.

         Secondary storage or simply storage concerns any storage device designed to retain data, information and instructions in a permanent form.

It is non volatile meaning that the data, information, programs are maintained when the device is powered down.