Types of Secondary Storage Devices

Storage Devices

A storage device is used for storing data files and objects. These objects can store information temporarily and permanently. They may be inside the system or outside. Following are the types of storage devices

1. Magnetic storage device
2. Optical storage devices
3. Flash storage
4. Cloud

Magnetic storage devices

Magnetic storage devices are used for storing data permanently using a magnetized medium. Read/ write activities are easy on these devices. A hard disk is one type of magnetic storage.

Hard disks are also known as hard drives or hard disk drives which are used to store data files and objects on it permanently. It is capable of storing more than 200 GB of data. It contains the stack of disks that are mounted internally inside a proper case as shown in the figure.

Optical storage devices

Optical storage devices store and read data using light on disks called optical disk. The most common types of optical storage devices are drives that read and write CDs, DVDs, and Blu-ray discs.

• CD-ROM
• A Compact Disc-Read Only Memory is a disk that can be read by a computer with an optical drive but it cannot be erased or altered.
• CD-R
• CD-Recordable are discs that can be written once only.
• CD-RW
• CD-Rewritable discs can be written multiple times.
• DVD-R
• A Digital Versatile Disc-Recordable is a type of optical media used for storing digital data. It is the same size as a CD but has a larger storage capacity of around 4.7 GB. Some DVDs are formatted specifically for video playback, while others may contain different types of data, such as software programs and computer files.
• DVD-RW
• A Digital Versatile Disc- Rewritable is a DVD that can be written multiple times.
• Blu-ray discs (BD)
• Blu-ray was developed by Blu-ray Disk Association (BDA) for recording and playing back high-definition (HD) video and for storing large amounts of data. While a CD can hold 700 MB of data and a basic DVD can hold 4.7 GB of data, a single Blu-ray disc can hold up to 25 GB of data.

Flash memory

Flash storage is a type of non-volatile memory that can be erased and rewritten electronically. These are solid-state media, meaning they consist entirely of electronic components instead of moving parts inside them. Types of flash memory are

• Solid State Drive (SSD)
  • Memory Cards
  • USB Flash drives

Solid-State Drive (SSD):

A Solid-State Drive (SSD) is a storage device that uses flash memory to store data. They have replaced hard disk drives and are now used in servers, desktop computers, and mobile computers and devices. With the passage of time, SSD has become smaller in size but increased its storage capacity. It can hold up to 12 TB of data.

Memory Card:

A memory card or a flash card is an electronic flash memory data storage device used for storing digital information. These are commonly used in electronic devices such as digital cameras, mobile phones, laptop computers, and tablets. These are expensive compared to other storage media.

USB flash drive:

A USB flash drive also known as a thumb drive is a flash memory storage that is plugged into a USB port. It is removable, rewritable, and much smaller than an optical disc. When it is plugged into a USB port, it is connected as an external drive. The maximum size of a USB flash drive available is 1 TB or more.

Cloud Storage:

Cloud storage is an online file storage we service for storing and accessing data. The physical storage spans multiple servers and the physical environment is typically owned and managed by a hosting company. The data here is available at all times. Following are the types of cloud hosting companies and the services provided by them.