European Computer Driving Licence Module 1 – Concepts of IT Section 1: General Concepts This presentation is an open source material on web, some modification made by: Sumayah Abu-Dawood The original source found on: 1

General Concepts ZInformation Technology (IT), General term used to describe the use of computers to process and transfer information., Can also refer to other office equipment (such as faxes and telephones) which contain tiny computers 2

Hardware and Software ZHardware (HW), Refers to the physical parts of a computer – those parts which you can see or touch. ZSoftware (SW), Primarily a list of instructions coded in a special way that computers can understand. Operating system software – e.g. Windows which works in the background and controls your software and hardware devices Applications software – e.g. Microsoft Word – software used to perform tasks 3

4 main parts of computer system ZMonitor (VDU) visual Display Unit: used to display results of processing. ZSystem Unit : this contains all the basic computer components that do all the hard work ZKeyboard: to enable text and commands to be input into the computer ZMouse: to enable the user to point and click at pictures and menus

Different Types Of Computer ZPersonal Computers (PC). ZLaptop/Notebook Computers. ZMainframe Computers. ZNetworked Computers. ZPersonal Digital Assistants (PDA )/ Handheld Computers. 5

Personal Computers (PC) ZAn essential tool for managers, humble office workers and home users ZTwo main types:, Desktop model – the system unit sits horizontally on a desk and the monitor is placed on top, Tower model – the system unit is vertical so can be placed on the floor to save desk space ZHardware devices (screen, keyboard and mouse) attached to the system unit (by a cable) are called peripheral devices 6

Notebook/Laptop Computers ZSimilar in specification to a personal computer ZMonitor and keyboard are integrated into a single unit ZCan be used from the mains or with a built-in rechargeable battery ZMore expensive than personal computers due to miniaturisation of computer components ZIdeal computer for business people and ICT trainers who are constantly on the move 7

Mainframe Computers ZLarge, fast and expensive ZUsed by large organisations such as utility companies, banks or multinational companies. ZConnect hundreds or thousands of users. ZUsers connect via terminals which are located in different cities or even abroad., Dumb terminals – these types of terminals cannot be used unless they are connected to the mainframe, Intelligent terminals – e.g. a personal computer connected to a mainframe, can also be used when not connected to the mainframe 8

Mainframe Computers 9

Networked Computers ZPersonal computers can operate as stand alone computers or they can be connected together as networked computer. ZMany networks use a server, which is a computer that controls access to HW, SW and other resources on a network. 10 ZPersonal computers connected to a server via network cards and cables ZThe software and data is stored on the central server rather than installed individually on each PC

Networked Computers 11 ZThe network also enables a fast Internet connection, printers and scanners to be shared. ZUsers access allocated resources via a user name and password. ZVery popular with small-to- medium-sized businesses, schools and colleges/adult education centres.

PDAs/Handheld Computers ZHandheld computer is a computer small enough to fit in one hand. ZSome use a stylus which you use to write or draw on the screen. ZRun very basic cut-down software such as calculator, address book and notepad functions ZCan be connected to a PC to synchronise data. ZPDAs can also be used as mobile phones and can access the Web to send and receive s. 12 stylus

Computer Components Computer Hardware Any physical part that you can see and touch. Software Programs that allow you to use computer but you can not see or touch. Pass ECDL413

Hardware Components Computer Hardware CPU Memory Storage Devices Input UnitOutput Unit Software Operating System Application Pass ECDL414

15 Central Processing Unit (CPU) ZThe main brain of the computer that performs the work and controls the transfer of information. ZThe speed at which CPU can process information is known as clock speed. ZSpeed is measured in Megahertz or Gigahertz., Megahertz (MHz)= 10 6 (1 million cycle per second)., Gigahertz (GHz): 10 9 (1 billion cycle per second). ZWhen CPU is on one chip, this is a microprocessor. ZExamples: Intel, AMD.

Computer Memory ZRAM (Random Access Memory):, Store information temporary., CPU transfers information from the hard disk drive to RAM., The more you have installed, the faster your computer will work., When the computer is switched off, anything stored in RAM is lost, Volatile memory ZROM (Read Only Memory):, Store information permanently., Used to store important information that the CPU needs to keep the PC running., ROM can only be accessed by the CPU and cannot be changed., The information doesn't lose its content when power is switched off., Information stored in ROM can be used repeatedly, Nonvolatile memory. 16 Memory is a chip that holds data waiting to be processed & instruction waiting to be executed. There are two kinds of memory:

Computer Memory 17 RAM Main memory Volatile memory ROM Secondary memory Nonvolatile memory

18 How RAM is work??? ZSwitch on the computer, The processor transfers operating system software from the hard disk drive to RAM., The Windows desktop appears. ZDouble-click on the Word icon., The processor transfers the software from the hard disk drive to RAM. ZOpen a Word document, The processor transfers the file information into RAM so you can see it and make changes to it. ZIf you don’t SAVE the document, the changes will be lost when you switch off the computer!

19 How ROM is work??? ZSwitch on your computer. ZA Power On Self Test (POST) and boot-up are carried out to make sure your CPU, memory chips and other components are working:, If they are, then information is transferred to RAM to start up your operating software., If not, then an error message will appear on screen. ZThe PC start-up software is stored in ROM so it can be used time and time again.

20 How memory is measured ZRAM is divided into millions of units called Bytes. ZEach byte contains 8 bits, which represent s one character ZMemory sizes :It’s the number of bytes the chip or devices has available for storage Z1 kilobyte (KB) =1024 bytes Z1 megabyte (MB) =1024 KB Z1 gigabyte (GB) =1024 MB Z1 terabyte (TB) =1024 GB E :::::: One BYTE RAM 8 bits represent (4) byte

21 File Sizes ZA simple Word document will measure approx 20Kb ZA 12 page report with pictures will take up much more space – maybe 300Kb ZA 100 page user manual with photos and screenshots could be at least 2Mb in size ZMicrosoft Excel, for example, takes up approx. 6Mb of hard disk space

22 Input devices ZThese are devices used to put data into the computer KeyboardLight pen MouseScanner(OCR) TrackballJoystick Microphone (Voice Recognition) Digital camera

23 Output Devices Monitors (VDU) ZCome in 15”, 17”, 19”, 21” screen sizes., Picture is made up of millions of dots called pixels, Picture quality depends on number of pixels going across and down the screen ZResolutions, Resolution is the number of horizontal and vertical pixels in a display device., 800 x 600 is typical of a 15” screen, 1600 x 1200 is typical of larger screens ZTwo different types, CRT monitors – similar to a TV screen, TFT monitors – much more slim line

Monitors 24

Monitors 25

26 Output Devices - Printers ZInkjet printers, Mainly used by home users, Black and white or colour printing, Medium in quality and cost. ZLaser printers, Used in most offices., Black and white or colour print, High price but suitable for large number of prints.

27 Output Devices - Printers ZDot matrix printers, Very noisy and low print quality., Low cost, use to print invoice, schedule, appointments. ZPlotter, Used mainly by architects to produce high quality prints such as: building plans, posters.

28 Output Devices ZSpeakers:, Connect to a soundcard supplied with multimedia PCs that acts as (stereo)., Speech synthesiser: program is able to transfer written text into audible speech.

29 Input/Output Devices ZTouch screen, Allows the user to touch an area of the screen rather than typing from a keyboard, Used mainly in tourist offices, bus information kiosks and Job Centres ZModem, Use to transfer telephone signal to digital or vs..