Secondary Memory of Computer & Different types of Secondary Memory

All of you must be using the computer and must be storing your important data in the computer storage device. Where you store that data is called secondary memory or secondary storage.

In today’s article, we are going to discuss the secondary memory of computer, types of secondary memory and the difference between primary and secondary memory.

If you do not know about the secondary memory of computer and want to get complete information, then this article is for you. In this article, we have been given complete information about secondary memory, after reading this you will not need to read the book or visit any other site. So, without delay, let’s get started.

What is secondary memory of computer?

Secondary memory is the largest storage of the computer and data can be stored in it for a long time. Since data is permanently stored in it, this memory is also called non-volatile memory. If the power of the computer is turned off, then the data stored in the secondary memory is not erased. Means, if that data is needed in future, then it can be extracted from this memory.

It is used externally in the computer. It connects to the motherboard through a connector. Its storage is much more than the primary memory. For this reason, the user stores large files and user important data in this memory and if needed, the user can manually correct that data.

CPU cannot directly access the data from secondary memory. Therefore, with the help of the primary memory, the CPU accesses the data of the secondary memory and processes it.

Secondary memory is slower than primary memory, so its price also works with primary memory. We can transfer the data stored in this secondary memory from one computer to another. That’s why it is also called auxiliary memory.

Some popular examples of secondary memory are: Hard drive, Floppy drive, Pen drive, Memory card, etc.

Types of secondary memory of computer

Basically, all the external storage devices used in the computer come under secondary memory. This secondary memory is mainly divided into 4 parts.

  • Magnetic Disk
  • Magnetic Tape
  • Optical Disk
  • Flash Memory
  • Cloud Storage

Magnetic Disk

It is used as the main secondary memory in computers. A magnetic disc consists of a circular metal plate covered with a layer of magnetic material. The user’s data is stored on the surface of these disk plates.

A metal plate called platter is attached to the magnetic disk. Apart from this, a mechanical arm is also attached to it. Its job is to receive data from the surface of the platter, which means to perform read and write operations.

It is a non-volatile memory that does not lose the stored data even when the power is turned off. The magnetic disk is not more costly, but its accessing power is slower than other memory.

Some examples of magnetic disk are Hard drive, floppy drive, Zip disk, etc.

Hard Drive

In an ordinary computer, the hard drive is the main storage device of the computer. In which all the files of the computer like operating system, utility software, and important data etc. are stored for a long time. Because of this hard drive is also called permanent storage device.

Basically, it is called the external part of the computer. But the hard drive fits inside the computer case and connects to the motherboard via a PATA, SATA, or SCSI cable.

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Floppy Drive

Floppy drive is a type of magnetic disk. It was used in earlier times. People stopped buying floppy drives after hard drives came into the market. The storage of floppy drives was much less than the hard drives.

There were two types of floppy drives. One was 5.25 inches, with a storage capacity of 3.50 KB to 2.44 MB. and the other was 3.2 inches. Whose storage capacity was 3.10 KB to 2.88 MB.

Zip Disk

A Zip drive is a small portable disk drive used to store and back up computer files. The storage capacity of the Zip drive is up to 250 MB. It looked similar to a floppy drive but had more storage than a floppy drive. Or because of being portable, people started using it more. But as the modern storage device started coming into the market, its market value gradually decreased.

Magnetic Tape

In earlier times, magnetic tapes were used to store audio and video data. All of you must have heard the name of VCR. In which movie cassettes used to come in earlier times. However, its use stopped long ago. It used to have a ribbon in which data was stored sequentially.

Optical Disk

Optical disc is a secondary storage. Which was used to store audio, video or software. Its storage capacity used to range from 700 MB to 4.5 GB. Its storage capacity was more than that of floppy drive and less than that of hard drive. Popular examples of this are CD drives, DVD drives, etc.

CD Drive

The full form of CD drive is Compact Disc. Its storage capacity used to be 700 MB. In today’s time, due to the availability of more memory storage devices in the market, its use has stopped. Although it was a plastic square-type plate. In which the data was stored.

DVD Drive

The full form of DVD was Digital Versatile Disk. Its storage capacity CD drive was more i.e. 4.7 GB. It was used to store audio, video, data or software. DVD looked similar to CD but had more storage capacity. Due to the arrival of more memory capacity storage devices in the market, its use also stopped.

Flash Memory

Flash memory is one of the popular secondary memory of computer. It was invented in 1980 by Dr. Fujio Masuoka. It is also called electronically erasable programmable read-only memory (EEPROM). This is because the data in the flash memory is electrically erased.

It is generally used for data backup, data transfer etc. Flash memory is also called non-volatile memory because the data stored in it is not destroyed when the power is turned off. The data is stored in the flash memory until the user deletes it.

Examples of the most commonly used flash memory are Pen drive, Memory card, SSD, etc.

Pen drive

Due to the pen drive being a portable storage device, we can carry it anywhere. It is built on the basis of EEPROM flash memory. That’s why data can be erased again and again and new data can be inserted.

A USB connector is attached to the pen drive so that it can be connected to the computer. In terms of storage, pen drives are larger than CD drives and DVD drives, but smaller than hard drives.

Memory Card

Memory cards are commonly used in mobiles, cameras, mp3 players, etc. It is mostly used to store video, audio, photo and personal data. Its size is smaller than other memory devices.


SSD stands for solid-state drive. It is a type of secondary storage device, which can store large amount of data forever, similar to an HDD.

Semiconductor is used in SSD due to which SSD is faster than hard disk. For this reason, nowadays all computer users have started using SSD in their computers and laptops. If SSD is used in the computer, then the performance of the computer becomes good.

Cloud Storage

Nowadays everyone likes to work online. That’s why many companies have started providing their own cloud storage. With this, the user can keep his data in cloud storage, which means, storing the data on the Internet.

Its advantage is that the user can access his data on any computer, mobile, laptop, which has internet, which has internet connection. No other storage device is required for this. The post you are reading is also stored in the cloud.

Using this cloud storage device is very easy. Some cloud storage companies provide some of their storage for free and if more storage is needed then the user has to pay a charge for that.

Features of Secondary Memory

  • Secondary memory is a non-volatile memory. The data stored in it does not get erased automatically after power off.
  • In this we can keep the data permanently for a long time.
  • The storage capacity of this memory is more than other types of memory.
  • Due to being installed externally in the secondary memory computer, we can take it anywhere and use it in any computer.

Difference between Primary and Secondary memory

Primary memorySecondary memory
Primary memory is volatile in nature.Secondary memory is non-volatile in nature.
In this memory, the data is stored in temporary basic.Data is stored in this memory on a permanent basis
CPU can directly access the data stored in primary memoryCPU cannot directly access the data stored in secondary memory. Primary memory is needed for this,
The storage capacity of this memory is less. But the speed is more.The storage capacity of this memory is high. But the speed was slow.
Primary memory cost is more than other memory.The cost of secondary memory is less.
Example of primary memory is RAM, ROM etc.Example of secondary memory is Hard drive, Pen drive, SSD, CD/DVD drive, Floppy drive etc.


What is secondary memory?

Secondary memory device is a non-volatile memory and permanent memory. It is connected externally to the computer. Large files and important data can be stored in it.

Why is secondary memory important in computers?

It is very important for the computer because its storage capacity is much higher than other memory and it is non-volatile in nature.

What is secondary memory of a computer give an example?

Examples of Secondary memory is Hard drive, Pen drive, Floppy disk, Memory Card, optical disk etc.

How many types of secondary memory in computer?

There are 5 types of secondary memory. Magnetic Disk, Magnetic Disk, Optical Disk, Flash Memory. Apart from this, cloud storage is also being used a lot nowadays.


In today’s article, we have talked about the secondary memory of computer, different types of secondary memory, the features of secondary memory and the difference between primary and secondary memory. I hope you all have understood about it. If you have any doubt regarding this article, then you can tell us. we will definitely solve your doubts.

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