Primary Memory or Primary storage (Memory)

Primary memory is also called primary storage or simply memory. It is built in within the computer.

Primary Memory :-
It is also called as main memory or internal memory. It is faster than secondary memory but it is very expensive. There are two types of primary memory:
1. RAM
2. ROM

RAM :-
RAM stands for Random Access Memory. We can read and write information in it. It is also called volatile or temporary memory because when we switch off the power supply, the whole information stored in it is erased. RAM is the working memory of the computer. All data and information must be in RAM, before processing.

ROM :-
ROM stands for Read Only Memory. The information of ROM is stored at manufacturing time but never altered afterwards. ROM is also known as Non-volatile memory because when we switch off the power supply, the information in ROM will not be erased. Basically, ROM stores the information which the computer needs all the time. The ROM basically stores computer configuration information.
The common four types of ROM are:
1. Masked ROM (Masked read only Memory)
2. PROM(Programmable Read only Memory)
3. EPROM (Erasable Programmable Memory)
4. EEPROM (Electrically Erasable Read only Memory)