This document defines and classifies different types of storage devices: - Storage devices are hardware used to store data and are classified as primary, secondary, or offline. Primary storage is fastest but deletes data on reboot, while secondary storage retains data regardless of power and offline storage can be removed. - Magnetic storage devices like hard disks and tapes use magnetism to read and write, while optical devices like CDs and DVDs use lasers. Other devices include USB drives and memory cards. - Storage devices functions are to read and write data, and they are essential components that allow computers to permanently save and access digital information.

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TIP
Assignment # 1
Names: *Syed Ahmed Khizar
*Syed Abdul Rafay Hassan
Topic: Storage Devices
DISCIPLINE: TS1
SUBJECT: Computer basics

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Table of Contents
Storage Devices:.................................................................................................................................2
Definition:......................................................................................................................................2
Example:........................................................................................................................................2
Classification:.................................................................................................................................3
1-Primary Storage Devices:..............................................................................................................3
Properties:..................................................................................................................................3
Example:.....................................................................................................................................3
2-Secondary Storage Devices:..........................................................................................................3
Properties:..................................................................................................................................4
Example......................................................................................................................................4
3-Off-line Storage Devices:..............................................................................................................4
Properties:..................................................................................................................................4
Example:.....................................................................................................................................4
Functions Of Storage Devices: .............................................................................................................5
Classification On Working Principle:.....................................................................................................5
1-Magnetic Storage Devices: ...........................................................................................................5
2-Optical Storage Devices:...............................................................................................................5
3-OtherStorage Devices:..................................................................................................................6
StorageDevices:
Definition: A hardware use to store data is called Storage device.
Example:
Correct Wrong
 Hard disk.
 CD (compact Dist)
 RAM
 Folder.
 PDF
 etc

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Classification: They are classified into three types:
1) Primary Storage Devices
2) Secondary Storage Device
3) Off line storage devices
1-PrimaryStorageDevices:
Primary storage is a storage location that holds memory for short periods of times while the
computer running.
Primary storage is also called internal memory, main memory, and primary memory.
Properties:
 Fastest memory in computer.
 After reboot it is automatically deleted.
Example:
 RAM
 Cache
2-SecondaryStorageDevices:
Secondary storage is a storage medium that holds information until it is deleted or overwritten
regardless if the computer has power.
Secondary storage is also called external memory and auxiliary storage.

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Properties:
 Any hardware or software problem can affect data.
Example:
 Hard drive
3-Off-lineStorageDevices:
Off-line storage that is removable and cannot be accessed by the computer once removed.
Properties:
 Any hardware or software problem does not affect the data.
Example:
 USB (Universal Serial Bus)
 Tape drive
 CD (Compact Disc)
 DVD (digital video disc / digital versatile disc)
 BD (Blu Ray Disc)
 etc

5. 5
Functions Of StorageDevices:
 Read data
 Write data
ClassificationOn WorkingPrinciple:
On the basis of working principles secondary and offline storage devices are classified into two
types;
1) Magnetic Storage Devices
2) Optical Storage Devices
1-MagneticStorageDevices:
 Use magnet to read or write data.
 In 1928, Fritz Pfleumer developed the first magnetic tape recorder, the first magnetic
device.
 Example; hard disk and magnetic tape drive.
2-OpticalStorageDevices:
 Use laser and work on principle of geometrical optics.
 Optical tape - more capacity than magnetic tape but not as cost effective.
 Example; CD, DVD and BD.

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3-OtherStorageDevices:
 Other storage devices work on the principle of electronic.
 Example: USB, Memory card, etc.