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What is Storage?

Storage is a process through which digital data is saved within a data storage device by means of computing technology. Storage is a mechanism that enables a computer to retain data, either temporarily or permanently.

Storage devices such as flash drives and hard disks are a fundamental component of most digital devices since they allow users to preserve all kinds of information such as videos, documents, pictures and raw data.

Storage may also be referred to as computer data storage or electronic data storage.

Storage is among the key components of a computer system and can be classified into several forms, although there are two major types:

  • Volatile Storage (Memory): Requires a continuous supply of electricity to store/retain data. It acts as a computer's primary storage for temporarily storing data and handling application workloads. Examples of non-volatile storage include cache memory and random access memory (RAM).

  • Non-Volatile Storage: A type of storage mechanism that retains digital data even if it’s powered off or isn’t supplied with electrical power. This is often referred to as a secondary storage mechanism, and is used for permanent data storage requiring I/O operations. Examples of volatile storage include a hard disk, USB storage and optical media.

Storage is often confused for memory, although in computing the two terms have different meanings. Memory refers to short-term location of temporary data (see volatile storage above), while storage devices, in fact, store data on a long-term basis for later uses and access. While memory is cleared every time a computer is turned off, stored data is saved and stays intact until it’s manually deleted. Primary or volatile storage tends to me much faster than secondary storage due to its proximity to the processor, but it’s also comparably smaller. Secondary storage can hold and handle significantly larger sizes of data, and keeps it inactive until it’s needed again.

Storage devices include a broad range of different magnetic, optical, flash, and virtual drives. They can be either internal (if they’re part of the computer’s hardware), external (if they are installed outside the computer), or removable (if they can be plugged in and removed without opening the computer). Storage also includes many forms of virtual and online storage devices such as cloud to allow users to access their data from multiple devices.

Common storage devices that are in use or have been used in the past include:

  • Hard disks.

  • Flash drives.

  • Floppy diskettes.

  • Tape drives.

  • CD-ROM disks.

  • Blu-ray disks.

  • Memory cards.

  • Cloud drives.

After a software command is issued by the user, digital data is stored inside the appropriate device. Data size is measured in bits (the smallest unit of measure of computer memory), with larger storage devices being able to store more data.

Storage capabilities have increased significantly in the last few decades, jumping up from the old 5.25-inch disks of the 1980s which held 360 kilobytes, to the modern hard drives which can hold several terabytes.

Difference Between Memory and Storage in Computers

Understandably, many computer users consider memory and storage to be the same thing. Those who realize that there is a difference between the two often cannot identify this difference. If you are unsure about the difference between memory and storage in computers, this article will enlighten you.


The term memory refers to the component within your computer that allows you to access data that is stored for a short term. You may recognize this component as DRAM, or dynamic random-access

memory. Your computer performs many operations by accessing data stored in its short-term memory.

Some examples of such operations include editing a document, loading applications and browsing the Internet. The speed and performance of your system depends on the amount of memory that is installed on your computer. If you have a desk and a filing cabinet, the desk represents the memory of your computer. Items you will need to use soon are kept in your desk for easy access. However, not much can be stored in a desk due to its size limitations.


Whereas memory refers to the location of short-term data, storage is the component of your computer that allows you to store and access data on a long-term basis. Usually, storage comes in the form of a solid-state drive or a hard drive. Storage allows you to access and store your applications, operating system and files for an indefinite period of time.

While the desk represents the computer's memory, the filing cabinet represents the storage of your computer. Items that must be kept yet won't necessarily be accessed soon are stored in the filing cabinet. Due to the size of the filing cabinet, many things can be stored.

An important distinction between memory and storage is that the former clears when the computer is turned off. On the other hand, storage remains intact no matter how many times you shut off your computer. Therefore, in the desk and filing cabinet analogy, any files that are left on your desk when you leave the office will be thrown away. Everything in your filing cabinet will remain.

Why is storage needed in a computer?

Without a storage device, a computer cannot save or remember any settings or information and would be considered a dumb terminal.

Although a computer can run with no storage device, it would only be able to view information, unless it was connected to another computer that had storage capabilities. Even a task, such as browsing the Internet, requires information to be stored on your computer.

Why so many different storage devices?

As computers advance, the technologies used to store data do too, right along with higher requirements for storage space. Because people need more and more space, want it faster, cheaper, and want to take it with them, new technologies have to be invented. When new storage devices are designed, as people upgrade to those new devices, the older devices are no longer needed and stop being used.

For example, when punch cards were first used in early computers, the magnetic media used for floppy disks was not available. After floppy diskettes were released, they were replaced by CD-ROM drives, which were replaced by DVD drives, which were replaced by flash drives. The first hard disk drive from IBM cost $50,000, was only 5 MB, big, and cumbersome. Today, we have smartphones that have hundreds of times the capacity at a much smaller price that we can carry in our pocket.

Each advancement of storage devices gives a computer the ability to store more data, and save and access data faster.

What storage device has the largest capacity?

For most computers, the largest storage device is the hard drive or SSD. However, networked computers may also have access to larger storage with large tape drives, cloud computing, or NAS devices. Below is a list of storage devices from the smallest capacity to the largest capacity.

There are exceptions to the list.

  1. Punch card

  2. Floppy diskette

  3. Zip disk

  4. CD

  5. DVD

  6. Blu-ray disc

  7. Flash jump drive

  8. Hard drive / SSD

  9. Tape drive

  10. NAS / Cloud Storage

Examples of computer storage

Magnetic storage devices

Today, magnetic storage is one of the most common types of storage used with computers. This technology is found mostly on extremely large HDDs or hybrid hard drives.

  • Floppy diskette

  • Hard drive

  • Magnetic strip

  • SuperDisk

  • Tape cassette

  • Zip diskette

Optical storage devices

Another common type of storage is optical storage, which uses lasers and lights as its method of reading and writing data.

  • Blu-ray disc

  • CD-ROM disc

  • CD-R and CD-RW disc.

  • DVD-R, DVD+R, DVD-RW, and DVD+RW disc.

Flash memory devices

Flash memory has replaced most magnetic and optical media as it becomes cheaper because it is the more efficient and reliable solution.

  • USB flash drive, jump drive, or thumb drive.

  • CF (CompactFlash)

  • M.2

  • Memory card

  • MMC

  • NVMe

  • SDHC Card

  • SmartMedia Card

  • Sony Memory Stick

  • SD card

  • SSD

  • xD-Picture Card

Online and cloud

Storing data online and in cloud storage is becoming popular as people need to access their data from more than one device.

  • Cloud storage

  • Network media

Paper storage

Early computers had no method of using any of the technologies above for storing information and had to rely on paper. Today, these forms of storage are rarely used or found. In the picture is an example of a woman entering data to a punch card using a punch card machine.

  • OMR

  • Punch card




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