Computer Storage Devices

8 min readOct 17, 2021

Computer storage is a technology consisting of computer components and recording media that are used to retain digital date. It is a core function and fundamental component of computers.

The central processing unit (CPU) of a computer is what manipulates data by performing computations. In practice, almost all computers use a storage hierarchy, which puts fast but expensive and small storage option close to the CPU and slower but less expensive larger options further away. Generally the fast volatile technologies (which lose data when off power) are referred to as “memory”, while slower persistent technologies are referred to as “storage”.

Even the first computer designs, Charles Babbage’s Analytical Engine and Percy Ludgate’s Analytical Machine, clearly distinguished between processing and memory (Babbage stored numbers as rotations of gears, while Ludgate stored numbers as displacement of rods in shuttles). This distinction was extended in the Von Neumann architecture, where the CPU consists of two main parts: The control unit and the arithmetic logic unit (ALU). The former controls the flow of data between the CPU and memory, while the latter performs arithmetic and logical operations on data. (htt)

Why we use computer storage devices???

Without a storage media, a computer can’t save any necessary data. Thus, it cannot remember anything just like a dumbox. Without data storage, the computer cannot do simple tasks such as open a document, watch a video and take a screenshot and so on. A storage device any type of computing hardware that is used for storing, porting or extracting data files and objects. Storage devices can hold and store information both temporarily and permanently. They may be internal or external to a computer, sever or computing device. (htt1) Also a storage device is piece of computer hardware used for saving, carrying and pulling out data. It can keep and retain information short-time or long-time. Short-time storage is where the processor does its work, where programs run and where information is stored while it’s being worked on. On the other hand, long-time storage allows information to be saved and recalled for later use like putting clothes in a closet or all your junk in a storage unit. Media storage is the place where things go when the microprocessor is not directly working on them but from where stuff can be retrieved later, if need be. These are usages of storage devices. (htt2)

There are four types of storage:

1.Primary Storage

2.Secondary Storage

3.Tertiary Storage

4.Off-line Storage

Primary Storage

Primary storage is a key component of a computer that holds data, programs and instructions that are currently in use.

Primary storage is located on the motherboard. As a result, data can be read from and written to primary storage extremely quickly. This gives the processor fast access to the data and instructions that the primary storage holds. (htt3)

There are three types of primary storage: RAM, ROM, Cache

Secondary Storage

Secondary storage is non-volatile, long-term storage. Without secondary storage all programs and data would be lost the moment the computer is switched off.

Example: Hard disk

However not all computers require secondary storage. Embedded computers such as those found in a washing machine or central heating system, do not need to store data when the power is turned off. The instructions needed to run them are stored in read-only memory (ROM) and any user data held in RAM. (htt3)

Tertiary Storage

Typically it involves a robotic mechanism which will mount and dismount removable mass storage media into a storage device. It is a comprehensive computer storage system that is usually very slow, so it is usually used to archive data that is not accessed frequently. This is primarily useful for extraordinarily large data store, accessed without human operations.

Examples: magnetic tape, optical disk

Off-line storage

off-line storage is a computer data storage on a medium or a device that is not under the control of a processing unit. The medium is recorded, usually in a secondary or tertiary storage device and then physically removed or disconnected. It must be inserted or connected by a human operator before a computer can access it again. Unlike tertiary storage, it cannot be accessed without human interaction. Off-line storage is used to transfer information, since the detected medium can easily be physically transported. Additionally its useful for cases of disaster, where for example, a fire destroys the original data, a medium in a remote location will be unaffected, enabling disaster recovery. Off-line storage increases general information security, since it is physically inaccessible from a computer and data confidentiality or integrity cannot be affected by computer-based attack techniques. (htt)

There are four types of computer storage devices:

1.Magnetic storage devices

2.Optical storage devices

3.Flash memory devices

4.Online cloud storage devices

Magnetic storage devices

Magnetic storage is the storage of data on a magnetized medium. This storage uses different patterns of magnetization in a magnetizable material to store data and is a form of non-volatile memory. The information is accessed using one or more read/write heads. This storage media, primarily hard disks are widely used to store computer data as well as audio and video signals. In the field of computing, the term magnetic storage is preferred and in the field of audio and video production, the term magnetic recording is more commonly used. The distinction is less technical and more a matter of preference. Other examples of magnetic storage media include floppy disks, magnetic tape and magnetic stripes on credit cards.

Some examples are: magnetic tape, floppy disk and hard drives.

Optical storage devices

In computing, an optical disc drive (ODD) is a disc drive that uses laser light or electromagnetic waves within or near the visible light spectrum as part of the process of reading or writing data to or from optical discs. Some drives can only read from certain discs, but recent drives can both read and record also called burners or writers (since they physically burn the organic dye on write-once CD-R, DVD-R and BD-R LTH discs). Compact discs, HD DVDs, DVDs and Blu-ray discs are common types of optical media which can be read and recorded by such drives. (htt)

Flash memory devices

Flash memory is an electronic non-volatile computer memory storage medium that can be electrically erased and reprogrammed. The two main types of flash memory, NOR flash and NAND flash are named for the NOR and NAND logic gates. NOR flash use the same call design, consisting of floating gate MOSFETs. They differ at the circuit level depending on whether the state of the bit line or word lines is pulled high or low. In NAND flash, the relationship between the bit line and the word lines resembles a NAND gate in NOR flash it resembles a NOR gate.

Some examples are: computer’s BIOS chip, compact flash, smart media and memory stick (htt)

Online cloud storage devices

Online cloud storage is off-site storage that’s maintained by a third party. This storage safely and securely saves your data to a remote database so you do not have to store your data and files to your computer hard drive or other storage device. This storage has many advantages over hard drive storage. 1st you do not have to physically possess the storage device as you would with a flash drive, for example, so you do not run the risk of losing irreplaceable data. 2nd cloud storage makes it easy to share content. Just share a Dropbox folder with a coworker and they can instantly access the content within it. Another great reason to use cloud storage is the cost savings. It’s much more affordable and smart to buy unlimited cloud storage for a nominal fee rather than buying and maintaining lots of hard drive storage space.

Some examples are: Dropbox, iCloud, Google drive, Microsoft One Drive, IDrive, Mega, Box, pCloud (htt)

What are the storage devices used today???

In the present, we use Digital Storage. Because of development of the technology. Then we talk about digital storage. What is the mean of digital storage? Digital data storage is essentially the recording of digital information in a storage medium, usually by electronic means. The storage device typically enables a user to store large amounts of data in a relatively small physical space and makes sharing that information with others easy. The device may be capable of holding the data either temporarily or permanently. Digital data storage devices have many uses. For example, computers usually rely upon information storage to function. Storage media can also be used to back up important information (storing digital data can involve durability and reliability issues, so making independent copies of information is normally a sensible precaution). Some storage devices are also portable, meaning that they can be used to transfer information from one computer to another. Digital data storage media generally fall into one of five categories: magnetic storage devices, flash memory devices, optical devices, online/cloud storage and paper storage. I will give one or more examples of each category below. (htt4)

01. Hard Disk

02. Floppy Disk

03. Tapes

04. Compact Devices (CD)

05. DVD and Blu-ray Disks

06. USB Flash Drives

07. Secure Digital Cards (SD Cards)

08. Solid-State Drives (SSD)

09. Cloud Storage

10. Punch Cards.