Page 20 - Computer - 3

Knowledge Discovery Subject Enrichment

The motherboard is also known as the system board. It is the main
circuit board of a computer. All other hardware devices are either

fixed on the motherboard or connected to it through cables.

Storage Devices
The memory unit of the CPU can hold only a limited amount of data temporarily. Storage
devices are hardware devices that can store large amounts of data permanently in the
form of files. Storage devices are both input as well as output devices, as they let you

read from and write data to the device. Let us learn about some storage devices.

Hard Disk

A Hard disk is the main storage device in a computer. It is a thin circular
metallic disk coated with magnetic material and encased in a metallic
box. The metallic disk rotates inside its case to read and write data. A

hard disk can be internal, fixed inside the computer or external, that can
be carried anywhere. Their storage capacity is from 500 GB upto 4 TB. Hard Disk

Solid State Disk (SSD)

A Solid State disk, or SSD, is similar to a hard disk but contains no
moving parts. Its read and write speeds are much faster than that
of a hard disk. SSDs are commonly used in laptops. Their storage

Solid State Disk (SSD) capacity varies from 256 GB to 2 TB.

CD/DVD/BD
CD stands for Compact Disc. It is a circular disk on which data is written using optical

technology. Its storage capacity is usually upto 700 MB. It is commonly used to store
documents and files.

DVD stands for Digital Versatile Disc. It can store upto 8.4 GB of digital data. DVDs are
usually used to store movies and videos.
BD stands for Blu-ray Disc. It is used to store high-definition movies and videos. The

storage capacity of a BD is usually between 25 GB to 50 GB.

Compact disc (CD) DVD Blu-ray disc (BD)

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