Secondary memory is an auxiliary memory of the computer. The data that has to be permanently stored is kept in secondary memory. The CPU can not directly access the data from secondary memory. The data has to be initially copied to primary memory then only it can be processed by CPU. Accessing data is slower. Ex: Hard disk, floppy disk, CD, DVD, etc.
It is the main memory of the computer. Primary memory can be divided into two types of memory that are RAM (Random Access Memory) and ROM (Read Only Memory).
- RAM is both read and write memory. The data which has to be currently processed is kept in RAM which can be quickly accessed by the CPU. RAM is volatile and loses data if the power is switched off. RAM can be static or dynamic.
- ROM is a read-only memory; its content can not be altered. It has the instructions that are used when the system is booted up. ROM is a non-volatile memory i.e. it retains its content even if the power is switched off. The types of ROM are PROM, EPROM, and EEPROM.
Difference Between Secondary Memory and Primary Memory in Tabular Form
|Primary memory||Secondary memory|
|Primary memory is known as main memory.||It is the cheapest type of memory for computers.|
|Primary memory is quite fast.||It is very slow in contrast to primary memory.|
|Data is stored by the computer’s CPU for quick, easy, and direct access. Ex: Hard disk, etc.||It is stored on secondary storage devices such as hard drives, DVDs, CD-ROMs, and so on.|
|There are two kinds of primary memory namely RAM and ROM. It is temporary||In fact, it is often permanent.|
|Primary memory is the internal memory of the computer.||Secondary memory is the external memory of the Computer.|
|Primary memory is accessed by the data bus.||It can be accessed by input-output channels.|
|Primary memory is usually volatile.||It is a non-volatile memory.|