Page 50 - DCAP101_BASIC_COMPUTER_SKILLS

Mandeep Kaur, Lovely Professional University Unit 4: Secondary Storage Devices

Notes

Unit 4: Secondary Storage Devices

CONTENTS

Objectives
Introduction
4.1 Secondary Storage Devices

4.1.1 Sequential and Direct-Acess Devices
4.1.2 Optical Disk Drive
4.2 Input/Output Device
4.2.1 Input Devices
4.2.2 Output Devices
4.3 Latest Input Devices in Market

4.4 Latest Output Devices in Market
4.5 Summary
4.6 Keywords
4.7 Self-Assessment Questions
4.8 Review Questions
4.9 Further Readings

Objectives

After studying this unit, you will be able to:
• Explaion of the secondary storage device
• Understanding of input and output devices in computer
• Know ledge and understanding of latest input devices in market
• Knowledge of latest output devices in market

4.1 Secondary Storage Devices

Secondary storage devices, as indicated by the name, save data after it has been saved by the
primary storage device, usually referred to as RAM (Random Access Memory). From the
moment you start typing a letter in Microsoft Word, for example, and until you click on
“Save”, your entire work is stored in RAM. However, once you power off your machine, that
work is completely erased, and the only copy remaining is on the secondary storage device
where you saved it, such as internal or external hard disk drive, optical drives for CDs or
DVDs, or USB flash drive.
Primary storage of a computer system has following limitations:
1. Limited Capacity. It is often necessary to store many millions, sometimes billions, and
even trillions, of bytes of data in a computer. Unfortunately, the storage capacity of

LOVELY PROFESSIONAL UNIVERSITY 43