​​Memory Unit of computer mainly divided into two parts

1. primary memory

2. secondary memory​

​

​Primary Memory

​It is also called internal or main memory

​It is of two type-

1. RAM - Random Access Memory (It is volatile memory)​

2. ROM - Read Only Memory (It is permanent memory)

RAM (Random Access Memory)

​ReIt is temporary in nature hence called volatile memory.

https://en.wikipedia.org/wiki/Random-access_memory​

ROM (Read Only Memory)

​It is permanent in nature. The types of ROM are given below-

1. PROM (Programable Read Only Memory)

2. EPROM (Erasable Programable Read Only Memory)

3. EEPROM (Electronically Erasable Programable Read Only Memory)

https://en.wikipedia.org/wiki/Read-only_memory​