Basic concepts of IT

The Basics – What is Information?• Information is data processed for some purpose • Information can only be considered to be 'real' Info if it meets certain criteria i.e.. What Is A Comp

Basic Concepts Of Information

Technology (IT)

Dheeraj Mehrotra

www.computerscienceexpertise.com

The Basics – What is Information?

• Information is data processed for some purpose

• Information can only be considered to be 'real' Info if it meets certain criteria i.e

• 1 it must be communicated to the recipient

• 2 it must be in a language that is understood

• 3 it must be in a suitable form

• 4 it must be relevant for achieving some

purpose

Information

-z is any form of communication that provides understandable and useful knowledge for the person receiving it.

What Is A Computer?

z A computer is a general purpose,

programmable device that is used

for the production and processing of information

z capable of calculating and storing

results

What do we mean by general

purpose?

Washing Machine, DVD Player

Computers Are Programmable

z Computers repond to instructions in the form of

programs

z Programs are written in order to make

computers behave in specific ways i.e word

processor, systems control

z Programs are stored in the Computer memory

How computers process information

z Computers accept inputs ( i.e data)

z The input is translated into binary numbers and

‘processed’

z The process produces output (i.e information)

z This sequence can repeat endlessly: outputs

can be inputs!

z Illustrating this - the ‘Black Box’ model

Processing - the ‘Black Box’ model

z We can think of a computer as a ‘black box’ :

3+5

8

Components of a Computer System

z Computer Systems are made up of:

z Hardware – the physical parts

z Software - the instructions or programs that control the hardware

z The Human Being – the brains behind the

whole system!

z Network Computer / Server

Computer Organisation – the Von Neumann model

z Most Computers are based on a model

proposed by John Von Neumann in 1946

z The ‘logical’ units of this model are:

program instructions sequentially

Computer Hardware components

z A typical PC System is made up of:

Hardware – The System Unit

z The central component of the system

z Houses:

The Processor (CPU)

z Types include Intel Pentium series, Celerion, AMD Athlon

z Chip at the heart of the computer- does the

calculations

z Speed is very important – measured in

megahertz (MHz): the faster the processor the more calculations performed per second

Random Access Memory (RAM)

z Used by the Computer as the working area

z Holds the working program, the data being

processed and the interim results

z Volatile - contents are erased if power is cut

z Can be accessed randomly: can get any piece

of data directly

z Faster than perminant storage

z Not to be confused with ROM (Read-Only

Memory)

Storage - Hard Disk

z Permanent Memory - records and stores all programs and data / information magnetically

z Larger than RAM - average 12 - 120GB

z Slower - involves mechanical movement

(read/write head, revolving disk)

Other types of Storage

z Floppy Disks

z CD/DVD ROM

z Zip Drive

z Magnetic Tape

z Generic name of all programs

z Made up of code interpreted by the hardware

z Written in programming languages - Java, C,

C++, Perl

z Two kinds of Software:

System Software

z Concerned with the computer itself: devices, file and storage management, error correction

z Main piece of SS: Operating System (OS)

z OS: the driving program of the computer

hardware

Applications Software

z Concerned with the world outside the computer

z Gives the computer its general purpose nature

z Used for the things you want the computer to do

z Common Examples - Word, Excel, Internet

Explorer

z Applications can be more specialised: e.g

Architecture package

How Software is made

z Involves a cycle of research, analysis, development and testing

z Systems Analysts - study the business processes and designs the software

z Programmers - develops the software

Problems with Software

z Software is complex

z Difficult to test comprehensivly

z Can have bugs: these can be trivial or major

z Symptoms of bugs

The Graphical User Interface (GUI)

z Represents all the program / computer

resources as icons

z Workspace represented graphically - creates

‘virtual’ documents

z More usable: led to wider use of computers

z Adds to the unique nature of the computer as

both a tool and a medium

Do’s and Don’t’s

away from the screen

z DON’T

the computer

temperature

is in operation

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