Transcript Essential Computing Concepts

Essential Computing
Concepts
Information System
An Information System has the following parts:
• People: the most important part
• Hardware: consists of the equipment: keyboard,
monitor, etc…
• Software: refers to the programs and its purpose is
to convert data into information
• Data: unprocessed facts, and once processed, it
becomes information
• Procedures: guidelines for people to follow when using
software, hardware, and data
What is a Computer?
Hardware
Software
Equipment
Programs
Any Computer System
Central processing unit
(CPU)
Input
Memory
Secondary Storage Devices
Hard Disk
Output
The Main Parts of a PC include:

The System Unit
 CPU
 Memory
or RAM (Primary
Storage)
Input / Output Devices
 Secondary storage devices
 Communication Devices

The CPU

Central Processing Unit (or processor)

The brain of the computer

Does all the calculation and processing
Input Devices

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Mouse
Keyboard
Scanner,
video camera,
etc.
Output Devices

Monitor/Screen (VDU – Visual Display Unit)

Printers
 Laser printers
 Inkjet

printers
Plotters, speakers etc.
Secondary Storage Devices

Provide Permanent Storage

Common Storage Devices:
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Hard (Fixed) Disk : Consists of 1 or more
rigid metal platters coated with a metal
oxide material for recording.
Floppy disk : Consists of thin, circular,
flexible plastic disk with magnetic
coating.
CD (Compact Disk) : Flat, round, portable,
metal storage. Uses laser technology.
DVD (Digital Versatile Disk)
RAM
CPU
HARDDISK
CD
Storage Capacity

The amount of information that can be stored in a
secondary storage device or in memory

A Bit (short for Binary digit) is the smallest unit of
storage in the computer. It represents a pulse of
electricity: Off = 0, On = 1

All numbers in the computer must be represented by
Bits (0 or 1). We cannot do this with decimal
numbers, so instead we use binary numbers.
Bits & Bytes

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Bit:
 All computers work on a binary numbering system, i.e. they
process data in one's or zero's. This 1 or 0 level of storage is
called a bit.
Byte:
 A byte consists of eight bits. A character needs one Byte of
storage.
Kilobyte:
 A kilobyte (KB) consists of 1024 bytes, approx 1,000 bytes.
Megabyte:
 A megabyte (MB) consists of 1024 kilobytes approx
1,000,000 bytes.
Gigabyte:
 A gigabyte (GB) consists of 1024 megabytes approx
1,000,000,000 bytes.
Storage Capacities
Temporary Storage

Random Access Memory (RAM) 256MB
Permanent Storage

Hard Disk
40 – 80 GB
CD (Compact Disk)
about 700 MB
DVD (Digital Versatile Disk) 8.5 GB

Floppy Disk


1.44 MB
Types of Computers
Supercomputer: The fastest and most
expensive high-capacity computers used by very
large organizations
Mainframe: Large computers, capable of great
processing speeds and data storage
Minicomputer: midrange computers used by
medium-sized companies
Microcomputer: Least powerful, small
computers, but most widely used (desktop,
Notebook or laptop, and Personal Digital
Assistants)
Computer = Hardware + Software

Hardware : The Equipment

Software : The Programs. A program is
a set of instructions which tell the
computer how to do its work
Types of Software

System Software : Programs to control the
operation of the computer.
 e.g.
Operating System (Windows, Unix, Linux etc),
Utility Programs, Device Drivers

Application Software : Programs for various
applications.
 e.g.
Programs for word processing, business, scientific
and other applications such as Microsoft Office which
consists of MS Word, MS Excel etc.
Types of Software
E.g. Operating system
such as Windows XP
Hardware
System
S/W
Back-end
Application
E.g. End-user programs
such as MS Word
Front-end
Occupational Health & Safety
Using the computer for long periods of time, may pose risk to health.
Check the following:
• Position of the monitor – Frame above screen should be level with eyes, so
that you look slightly down. Distance should be less than an arm’s length.
Avoid screen reflection and flickering.
• Posture of the user – Chair back upright, lower back supported, feet flat on
floor, Forearms should be horizontal, wrists straight and task materials
within comfortable reach of both hands.
Preventive exercises should be done before starting and during work.
• Eyes: Take frequent short rests: Look away from screen towards objects
20-30 ft away, or look outside the window far out, or close your eyes.
• Muscles: Do neck exercises. After every hour walk around, stretch
all muscles and perform whatever relieves the feeling of muscle fatigue/strain
Suggested reading: www.healthycomputing.com/office