Data Storage Types

Data storage is an important task performed by computers. Devices that are used to store information use different technologies and store information for a certain period of time. Computer data storage devices store information in digital forms. Data storage types are classified according to the basic task they perform, i.e. whether the storage device is used as a memory or it is used as a secondary storage device. Also, there are other different types of data storage devices used in the computers to store data. Let us take a look at these types in detail. The three basic computer data storage types are primary storage, secondary storage and tertiary storage.

Data Storage Types - Primary Storage

Basically, primary storage is the memory part of the computer itself. Primary storage includes the Random Access Memory (RAM) and Read Only Memory (ROM).

Random Access Memory (RAM)
Random access memory is used as a scratch pad by the computer processor to store information temporarily. The random access memory is a volatile memory that loses information as soon as you turn off the computer. However, the access rate of this type of memory is greater than the read only type of memory. Access rate of the memory is the time required by to get an access to the memory. Also, RAMs are a bit more expensive than the read only memory.

Read Only Memory
Read only memory (ROM) is a type of data storage that is used to store information permanently. Either the data is stored in this type of memory at the time of manufacturing or is stored by the computer user. But the data in this type of data storage cannot be changed once written (non-volatile). The access rate of this type of primary storage is less than that of the RAM. Lastly, the ROMs are not as expensive as the RAMs.

Data Storage Types-Secondary Storage

Hard disks, magnetic tapes and all other data storage devices are included in the secondary storage. They are external to the processor and are used to increase the storage capacity of the computer. The secondary storage is non-volatile and can retain information even after the computer is switched off. Following are the devices that are secondary storage devices:

Hard Drives
Hard drives are crucial secondary storage devices that are used in a computer. Again, there are different hard drive types. Hard disk drives are non-volatile and data is stored in a digital form on the platters that have magnetic surface. Earlier, the hard disk drives were used as a removable mass storage device. However, nowadays, the hard disks come as a complete sealed unit inside the CPU. Portable hard disk drives are also available now.

Blu-ray Discs
Blu-ray discs are often referred to as BD. These discs are often used by gamers and also for high definition video storage. According to the physical dimensions, the blu-ray discs are similar to that of the CDs and DVDs; however, the only difference is that the capacity of a blu-ray disc is very large as compared to CDs and DVDs. Blu-ray discs are optical storage devices.

The secondary storage also includes offline storage devices. Offline storage devices are those secondary storage devices in which information is stored and then they are disconnected from the computer. They include CDs and DVDs. The main aim of storing data offline is to increase the security of information, besides using up less space in the computer itself, and also act as a backup of data.

Compact Discs
Earlier, CDs were used to record audio files, but later on they started being used to store every type of information like video, audio and data. Compact discs (CD) are used to store information over a long period of time. CDs store information optically and are non- volatile.

Digital Versatile Disc (DVD)
DVDs store data in the same manner as that of the CDs. However, DVDs have a greater storage capacity than the CDs. A DVD have a capacity which is six times greater than the storage capacity of a CD.

Flash Memory
Flash memory is a further advancement in the read only memory with the difference that the information in the flash memory can be electrically erased within seconds. Also, the data that is stored in the flash memory can be changed according to the use.

Data Storage Types - Tertiary Storage

Tertiary data storage is the third data storage out of the three types of data storage. The tertiary devices includes the storage devices that are connected to the computer in the form of removable mass storage devices. Tertiary storage is often used to store those files that are rarely accessed by the computer user.

USB Flash Drives
USB flash drives are connected to the computer via the USB port of the computer cabinet and use the Universal Serial Bus (USB) interface to store information. They are rewritable and have in-built flash memory inside them.

These are the types of data storage used in computers. Advancing technologies these days are increasing the access rate and the capacity of these data storage devices.