Difference between Primary and Secondary memory

Memory is the storage space utilised by the computer for storing data and instructions, required for processing of the information.

Memory is of two types:

1) Primary (or) Main memory

2) Secondary (or) Auxiliary Memory

Now let’s look in brief at both types and their characteristics.

Primary memory:

1. It is the Main Memory of the computer where the currently processing data or information resides for faster access.
2. It is volatile by its nature, which means data in this memory is stored temporarily, and it does not retain data during a power outage.
3. It uses semiconductor chip technology, which has a minimum capacity of storage but fastly accesses the Memory by utilising the CPU. It is also expensive.

Types of Primary Memory:

• RAM (RANDOM ACCESS MEMORY)
• ROM (READ ONLY MEMORY)

RAM (RANDOM ACCESS MEMORY): RAM is most commonly known as Main Memory. It is known as cache memory as the information stored in this type of memory is lost when there is no power supply. Every operation on the computer first loads into the random access memory (RAM), which makes it faster to access. RAM is both read and write Memory. RAM can be static or dynamic.

ROM (READ ONLY MEMORY): ROM is a read-only memory. It is a permanent type of Memory, which stores the instructions that are essential to boot up the system. The user can not overwrite ROM as the information of ROM is permanently stored at the time of manufacturing by the computer manufacturer. It is a non-volatile memory as it retains the data even during power loss. The types of ROM are PROM, EPROM, and EEPROM.

Secondary Memory:

1. Secondary Memory is an auxiliary or external memory of the computer. All storage devices such as hard disk, optical disk, compact disk, flash drives, magnetic tapes, etc. which have high-storage capacities are known as Secondary memory.
2. The Central Processing Unit cannot directly access the data in secondary memory. As it requires the data to be initially copied to primary memory to be processed by CPU, this makes accessing data from secondary memory to become slower.
3. The secondary memory uses the input-output channels to access the data, making it non-volatile, i.e. the content of the secondary memory exists even in the absence of power.
4. As the computer can even work without secondary memory as it an external memory, these storage devices are available at cheaper rates.

Differences between Primary and Secondary memory: