Primary storage

      Read-only memory (ROM) 

1. Read-only memory (ROM) is a class of storage medium used in computers and other electronic devices.

   

   
   

   
   

   
   

   Random Acess Memory

   Alternatively referred to as main memory, primary memory, or system memory,Random Access Memory (RAM) is a computer storage location that allows information to be stored and accessed quickly from random locations within DRAM on amemory module. Because information is accessed randomly instead of sequentially like a CD or hard drive the computer can access the data much faster than it would if it was only reading the hard drive. However, unlike ROM and the hard drive RAM is a volatile memory and requires power in order to keep the data accessible, if power is lost all data contained in memory lost.