EXPLAIN KEYS AND TYPES OF KEYS IN DBMS

BASIC CONCEPT OF PRIMARY MEMORY 

PRIMARY MEMORY : It is also known as main memory.

*Types of primary memory : -

1. RAM : -

•   It stands for Random Access Memory. 
•  It was developed by Robbert dennard             in 1968.
• RAM is a memory which is used for storing running program in computer system.
• RAM is a volatile memory because all the data stored temporarily in RAM.

TYPES OF RAM : -

1.SRAM  : -

• It stands for Static Random Access Memory.
• It is a types of RAM which is used for built in cache memory.

2.DRAM : -

•  It stands for Dynamic Random access Memory.
• It is a types of RAM which is used for temporary storage of information in computer system.

2. ROM : -

• It stands for Read Only Memory.
• It was developed by Robbert Dennard in 1966.

ROM is a non volatile memory because all the data stores permanentaly in rom. 

TYPES OF ROM : -

• PROM  : - It stands for programable read only memory.

• EPROM : - It stands for electrical programable read only memory.

• EEPROM : - It stands for electrical erasable read only memory .

• FLASH MEMORY : - It is a memory which is developed in 1984 .