A computer system comprises several units that must work together for the computer to give the desired results. The storage unit is one of the must-have parts of the computer system. It stores information and instructions that are used to run functions on a computer. Additionally, this unit holds data either temporarily or permanently.
Without storage, a computer can’t execute any function, let alone boot. There are different computer storage types with different characteristics and functions. Learning these storage types and their strengths and weaknesses lets you decide the best choice.
Below are the different classes of computer storage and examples of each type. Let’s jump into it!
Main Types of Computer Storage
All storage devices, regardless of size or use, are classified into two main parts: primary storage and secondary storage. Both secondary and primary storage devices work together to create an ideal storage system. Here is more information on each storage type.
Primary storage devices are the devices found in the CPU that contain intermediate results, input data, and programs. They are located on the motherboard and are generally small in size. These devices are also called internal memory, main storage, or main memory.
Examples of primary storage devices include the ones detailed below.
Random Access Memory (RAM) is hardware that holds data temporarily and stores current data. For instance, if you have opened programs like Chrome, Word, and File Explorer, these are held in the RAM.
Besides, you can switch between different programs without opening them every time since they are stored in the RAM. This also explains why your system may hang if you open too many programs and your device has small RAM storage. If you have a device with a RAM of 1GB, it can be hard to multitask more than ten applications, especially if they are memory-demanding apps like some games.
The data in the RAM is lost or deleted after the computer turns off. Therefore, if your device turns off, you must reopen the previously running programs. RAM ranges from 1GB to around 64GB for different devices.
Types of RAM
There are three different types of RAM.
Static Random Access Memory (SRAM)
Static RAM is a type of memory that holds information for as long as the power is on. It retains data bits using circuits. It is mainly used in consumer electronics and mobile phones. Additionally, SRAM is used in automobiles, industrial equipment, and medical products such as hearing aids.
Dynamic Random Access Memory (DRAM)
Dynamic RAM is a memory that stores bits of data in memory cells, each bit in its memory cell. This is done through the use of transistors. DRAM is slower than SRAM but cheaper and occupies less space.
Synchronous Dynamic Random Access Memory (SDRAM)
Synchronous DRAM is an improved type of DRAM. It has pins that improve its performance and sync with the data connection between the microprocessor and the main memory. This is the most common type of RAM used in laptops and desktops.
Read-only memory (ROM) is a type of memory that stores data that is non-volatile, meaning the data cannot be edited. You can only read the data but cannot write. The data found in the read-only memory is stored there during its manufacture.
For instance, the instructions to turn on a computer are stored in the ROM. It also holds instructions for other electronic items like dishwashers. ROM storage devices have a size of between 4 and 8 megabytes.
Types of ROM
There are two main types of ROM.
Programmable Read-only Memory (PROM)
This type of ROM is programmed, and the information is stored during manufacture. This information stays on the ROM whether the computer is on or off.
Erasable Programmable Read-only Memory (EPROM)
With the Erasable Programmable ROM, altering the information stored on the ROM is possible. These are designed for programs that are used repeatedly but may need to be upgraded after a while.
Secondary Storage Devices
A secondary storage device holds data and programs in the long term. These devices store data until it is overwritten or deleted. Data usually comes from the primary storage and is saved in the secondary storage.
For instance, if you are working on a word document that you have not yet saved, it is held in RAM. When you save it, it moves from the RAM, which is primary storage, to the secondary storage. Similarly, when you open the document later for editing, it moves from the secondary to the primary storage. However, a copy of the original saved document is retained in the secondary storage.
Unlike data in the primary storage, data in the secondary storage is not lost after you turn off your computer. Secondary storage devices are also called auxiliary storage. They come in several types, each with its characteristic and unique functioning.
Below are the types of secondary computer storage and their examples.
Magnetic Storage Devices
Magnetic storage devices are those that write, re-write, and access data through magnetization. They have tiny electromagnets that create, read, and erase data stored as magnetized dots. These magnetic storage devices also have a magnetic rotating arm and a magnetic coating. Data in these devices is stored in sectors, spots, and tracks.
Let’s explore some examples of magnetic storage devices below.
Hard disks are the most common storage devices used in laptops and desktops. These drives have several circular disks called platters and a spindle around which the platters are arranged. These platters are non-magnetic but are coated with magnetic materials. A hard disk can be written and deleted as many times as possible without problems. Hard disk storage ranges from several gigabytes to terabytes.
A tape cassette is a rectangular container with magnetic tape that stores data. A tape cassette is also called a music cassette and is mainly used to store audio recordings. However, tape cassettes are less common nowadays since they have been replaced by modern, more advanced storage methods.
These magnetic storage types are packed inside a protective plastic envelope with a magnetic coating. Like tape cassettes, they are among the oldest types of storage devices and are, therefore, used sparingly due to their limited storage, among other limitations.
A super disk is like a bigger floppy disk. It is also called LS-120 or LS-240 and can hold up to 240 megabytes.
A magnetic card holds digital data encoded in a magnetic object or a magnetic strip found in the card. The card can have the size of a business card, but only a small part has magnetism. This magnetic part can hold information like passcodes for entering buildings or credit card balances.
Optical Storage Devices
An optical storage device uses laser beams to store and read data. These devices are also called optical memory or optical media. Optical devices offer more storage space than magnetic ones since the laser beams condense extensive data into smaller regions.
Examples of optical storage devices include:
Compact Disk (CD)
A compact disk, commonly known as CD, is a polycarbonate circular storage device that can hold up to 700 megabytes of data. It contains tracks and sectors where it stores data. A CD can be CD-R or CD-RW. CD-R means Compact Disk Read-Only; once data is stored on this disk, it cannot be erased. On the other hand, CD-RW means Compact Disk Read-Write. This disk allows the user to edit the data several times.
Digital Versatile Disk (DVD)
A DVD is a device that looks and functions like a CD but has a higher storage device. DVDs range from 4.7 gigabytes for single-layer DVDs to 8.5GB for double-layer DVDs.
DVDs are also of two types, DVD-R and DVD-RW. For DVD-R (Digital Versatile Disk- Read), data, once stored, cannot be edited. It is mainly used to store movies. For DVD-RW (Digital Versatile Disk Read Write), it is possible to edit the stored data.
A blu-ray disk is a device similar to DVDs or CDs but can hold much more data, up to 25GB. This drive uses a shorter wavelength than CDs and DVDs, thus has the ability to store more data. It uses a blu-ray reader that reads and writes information on the disk.
Flash Memory Devices
Flash memory devices are storage devices that use flash memory chips to write and hold data. These are solid-state devices, meaning that they have no moving parts. This gives them a faster response time than other storage devices with moving parts, such as hard disks.
Examples of flash memory devices are:
Solid State Drive (SSD)
A solid state drive is a device that stores data using non-volatile storage. Although they have the same purpose as hard disks, they are more efficient since they are lighter and faster in reading and writing data. Nevertheless, this comes at an extra price for SSDs. SSDs sizes range from about 100GB to several TBs.
USB Flash Drive
A USB flash drive, or a pen drive, is a storage device with flash memory. They are connected to computers or other devices through USB ports to read or write data. These drives are easy to write and read data and are easily portable. Their sizes range from several MB to about 256GB.
Memory cards are the most commonly used storage devices in game consoles, digital cameras, printers, and even smartphones. The device is small in size but can carry vast amounts of data. To edit or view the content of a memory card on a computer, you will need to use a memory card reader.
A secure digital (SD) card is similar to a memory card used in electronic devices like digital cameras and mobile phones. The card is small to fit in such small electronic devices. Its size ranges from 2GB and above.
Cloud and Virtual Storage
Cloud storage is a modern method of storage where data and information are stored in the cloud. Unlike other tangible methods of storage, cloud storage is intangible. You pay for the cloud space you need to the cloud providers.
Some commonly used cloud storage companies are Google, Amazon, and Microsoft. When you purchase cloud storage with any of these companies, they store your data in their data centers.
This type of storage is more reliable than other physical storage devices since you can access your content in any location if you have an account with the cloud storage service provider.
The generation and creation of digital data are on the rise constantly. Fortunately, computer specialists are well-equipped with storage devices to hold this data permanently or temporarily.
Get the storage device that is best equipped to store your data for secure storage. Additionally, if you still need to start using cloud storage, familiarize yourself with it, as this is the future of data storage.
- Hard Disk Explained: Everything You Need to Know
- Floppy Disk Explained: Everything You Need to Know
- Flash Memory
The image featured at the top of this post is ©Daniel Krason /Shutterstock.com.