Memory

A: Primary memory

Under Primary memory there are two type of memory : 1 Ram (Random Access memory) which is known as volatile and 2. Rom (Read only memory) which is know as non volatile

Classification of Ram : SRAM (Static Random access memory) and DRAM (Dynamic Random access memory)

Classifican of Rom : P-Rom (Programable read only memory) , EP-Rom (Erasable programable ready only memory), EE-Prom (Electrically erasable read only memory)

Classification of DRAM: EPM DRAM(Extended page mode dynamiv random access memory) , EDO DRAM(Extended data out dynamic random acess memory) , SD RAM(Syncronous dynamic access memory), RDRAM (Ranbus dynamic random access memory)

Classification of SD RAM: DDR1 (Double data rate), DDR2 (Double data rate 2), DDR3 (Double data rate 3), DDR4 (Double data rate 4).

B: Secondary memory : HDD (Hard disk drive) , CD/DVD, Floppy drive and SSD (Solid state drive)

1. Logical memory : Its not an actual memory but work as a memory

Memory : Memory is an essential component of digital device which is used to store the data on it permanently or temporarily .

• Volatile Memory : ITs store the data temporalily if you shutdown or restart the device all data will be errase . ex: RAM

• Non- Volatile Memory: Its store the data permanetly . it does not lose the data even after system shutdown or restart . Ex: ROM , HDD, CD, DVD.

  RAM Type DATA Transfer rateor speed

• EPM DRAM 100 MHz

• EDO DRAM 264 mbps

• SD RAM 133 MHz

• RD RAM 800 MHz

• DDR1 266/333/400 MHz

• DDR2 533/667/800 MHz

• DDR3 800/1600 MHz

• DDR4 1600/3200 MHz