Page 17 - TP_Modular_V2.1_Class3
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Secondary Memory
This memory is permanent in nature and is not
directly accessed by the CPU. It allows users Just like a tree stores water
to store data that may be easily retrieved. It in its trunk, a computer
stores information, like your
is cheaper as compared to primary memory.
drawings and games in its
Secondary memory devices are also called
storage devices.
secondary storage devices. They are divided
in three categories: Magnetic Disks, Optical
Discs and Flash Drives.
Magnetic Disk
A magnetic disk is covered with a magnetic coating. You can record and erase data
on a magnetic disk any number of times. The different types of magnetic disks are:
✶ Hard Disk: It consists of one or more magnetic disks called
platters. It is permanently fixed in the CPU box. It comes
in a variety of sizes with storage capacities as high as 5 TB
(TeraByte) or even more.
Hard disk
✶ External Hard Disks are also available. They are the hard
disks that can be connected to any computer with the help of a USB port.
Optical Disc
An optical disc is an electronic data storage medium that can be written to and
read using a low powered laser beam.
✶ Compact Disc (CD): The CD drive fitted in the
CPU box, reads information stored on a compact
disc (CD). CD is an external storage device. It
can hold upto 700 MB of data. The different
CD DVD types of CDs are CD-ROM, CD-RW and CD-R.
✶ Digital Versatile or Video Disc (DVD): DVDs are now widely used to store data.
A DVD is similar to a CD. It’s storage capacity is 4.7 GB, much higher than a CD.
Flash Drive
The Flash Drive is a small portable data storage device.
✶ Pen Drive: Pen drive is a storage device which can store a
large amount of data. It is connected to a computer using a
USB (Universal Serial Bus) port. It can be carried in your pocket
Pen drive
easily. Pen drive has storage capacity of upto 1 TB.
Computer Memory 15

