Igcse ict flash cards

Everything you need to know for IGCSE ICT Paper 1 (Important definitions written with '***')

Everything you need to know for IGCSE ICT Paper 1 (Important definitions written with '***')

Everything you need to know for IGCSE ICT Paper 1 (Important definitions written with '***')

Random Access Memory (RAM)

Temporary memory a computer uses to store information while it is processing.

Motherboard

A circuit board that contains all of the computer system's main components

Read Only Memory (ROM)

memory chips where the contents can be read but not written to and where the contents are retained when the power is removed

Video Card

An expansion card that generates the signals so that a video output device can display computer data such as text and graphics

Sound Card

an expansion card that allows a computer to send audio signals to audio devices such as speakers and headphones. Most computers now have the sound card integrated into the motherboard

Internal hard disk drive

a rigid magnetic material coated disk onto which programs and data can be stored and situated inside the casing of the computer

Examples of external hardware devices

• Monitors / screens • Keyboards and mice • External storage devices (HDD, pen drive, memory sticks) • Printers • Scanners • Speakers and microphones

Software

Programs for controlling the operation of a computer or for processing electronic data Software consists of sets of instructions that tell the computer hardware what to do. Software is written in a computer language, and there are quite a few different ones. Computer hardware is useless without software. Software is of two main types: applications software and system software

Applications software

Programs that are designed to carry out certain operations for a particular application. The formatting of text and the organisation of page layout can be performed using word-processing software, which is an example of this type software This type software cannot run on its own, it is dependent on the other type of software, system software.

Examples of Applications software

• Word processing software • Photo / video editing software • Database management systems • Spreadsheet software • Control software • Measuring software • Applets and apps • Graphics manipulation software

Applets

small application software that performs one specific task

System software

Programs that control the computer hardware directly by giving step-by-step instructions that tell the computer hardware what to do. It therefore operates and controls the computer hardware.

Examples of system software

• Operating Systems • Device Drivers • Compilers • Linkers • Utilities

Operating systems

A program or a suite of programs that controls the system resources and the processing using these resources on a computer.

Compilers

Programs that change the instructions written in certain programming languages such as BASIC into binary numbers. It converts the whole of a program written in the programming language into binary in one go. The program is then stored in binary and. when it runs, it runs much faster because no time is wasted translating it.

Device Drivers

Software used to supply instructions to the hardware on how to operate equipment that may be connected to the computer, such as printers, scanners, keyboard, mice, external hard disk drives, etc.

Linkers

Programs that are usually part of compiler. They take care of the linking between the code the programmer writes and the resources and libraries that make up the whole program file that can be executed.

Utilities

Programs that are provided as part of the system software and they help the user with everyday tasks

Examples of Utilities

• File maintenance • Creating new folders, copying files, renaming files, deleting files • Compressing files so that they take up less storage space, or can be transferred quickly over the internet • Compacting files on the hard drive so they can be found faster • Checking for and removing viruses • Formatting a disk ready for use • Burning CDs and DVDs

4 main components of a computer

• Input devices • Processor and internal memory • Output devices • Secondary storage devices

Main features of a GUI

W.I.M.P • Windows • Icons • Menus • Pointer

Benefits of GUI

• More user friendly - more obvious to new users to do simple tasks such as printing by clicking on printer icon • No commands to remember, simply click on icons or drop down menus • Much easier to find programs that are running - e.g. word processing software in one window, spreadsheet in another window • Enables data to be passed easily from one software to another - via cut/paste, drag/drop

Drawbacks of GUI

• Takes up more hard disk space when being stored • Requires more memory (RAM and ROM) • A more experienced user may find that typing in commands is quicker than moving the mouse or clicking • A powerful processor is needed to run the latest version of the interface

Benefits of CLI

• If the user is experienced in using the interface, it can be faster to type commands rather than move the mouse to click on icons and menus to issue the same commands • Uses less hard disk space when being stored • Does not need a powerful processor to run • Does not need as much memory (RAM and ROM)

Drawbacks of CLI

• You need to learn and remember lots of commands • Commands must be issued in a specific order otherwise the commands will be rejected

Advantages of Desktops compared to laptops

• Usually have higher specifications (RAM, ROM, disk space, processor, etc.) • The keyboard is separate to the screen, and both can be adjusted, so the user is less likely to suffer from backache or RSI • They cheaper to buy, repair or upgrade • The full sized keyboard and mouse are are easier to use compared with the smaller keyboard and pointing device used with a laptop

Disadvantages of Desktops compared with laptops

• They are not portable because they are large and consist of several components • There are many wires which need to be disconnected when moving the computer, and this takes time • If office work needs to be done at home, you cannot easily take the computer home, so you have to spend time copying files onto removable media

Benefits of Laptop compared with desktops

• Much smaller and lighter, so easily transportable • Can be used on your lap when there are no flat surfaces on which to work • They have a battery which enables them to be used away from a power supply • Files do not have to be transferred between work and home which saves time

Drawbacks of Laptop compared with desktop

• The smaller keyboards are more difficult to use • The pointing device is harder to use than a mouse, although a mouse can be connected to the laptop and can be used where there is a flat surface • The base of the laptop becomes hot, making it uncomfortable when used on your lap • As they are portable and therefore can be used in public spaces, they are more likely to be stolen • They have a limited battery life, so you need to carry an adapter so that they can be recharged

Characteristics of Tablet Computers

• A camera • Speakers • Touch screen • Microphone • Webcam • Bluetooth • Handwriting recognition • Ability to use Wi-Fi • Ability to use 4G/5G telephony

3 Biometrics

• Fingerprint • Pattern on retina • Pattern on Iris

Uses of fingerprint scanning

• Used for recording attendance in school/college • Used for access to buildings and rooms • Used to restrict access to computers/smartphones • Used to restrict access to countries at border control, airports, etc.

Uses of retinal scanning

• Used for passport control • Used for access to buildings and rooms

Advantages of Robots***

• Can operate continuously, 24 hours per day and 7 days per week • Less expensive to run as you don't have to pay wages • Can work in dangerous places (e.g. bomb removal) • Can easily change the way the device works by re-programming it • More accurate than humans • Can react quickly to changes in conditions

Disadvantages of Robots

• Initial cost of purchasing robots can be high • Equipment can go wrong • Needs specialist to program, which is expensive • Fewer people needed so leads to unemployment

Advantages of keyboard for data entry

• Text appears on the screen as you type so it can be easily checked for accuracy (visual verification) • They are ideal for applications such as word processing or composing emails where you have to create original text • Can be used for other instructions (e.g. CTRL+P to print)

Disadvantages of using keyboard for data entry

• It is a slow method for entering large amounts of text compared to methods such as dictating or scanning text in • It can be inaccurate as it it easy to make typing mistakes • It can be frustrating if you do not have good typing skills • Typing for a long time can cause a painful condition called RSI

Numeric Keypad uses

• ATM - enter PIN number • Chip and PIN machines

Advantage of using Numeric Keypad

Smaller than a full keyboard, making it easier to carry or move, e.g. at a shop counter

Disadvantages of using Numeric keypad

• Small keys might be difficult for some people to see • Keys might be arranged differently, e.g. on a phone vs on a chip and PIN pad

Advantages of using a mouse

• Easier than using a keyboard to select or move items • Enables rapid navigation through an application • Small, so it occupies only a small area on the desktop

Disadvantages of using a mouse

• Hard to use if the user has limited wrist or finger movement • Needs a flat surface, so it can't be used on the move

Advantages of using touchpad

• Can be used on the move, where there is no flat surface on which to use a mouse • There is no extra device to carry as the touchpad is built into the computer • It is faster to navigate through an application compared to using a keyboard

Disadvantages of using touchpad

• They are hard to use if the person using it has limited wrist or finger movement • They are hard to use for actions such as 'drag and drop' • Controlling the pointer is more difficult compared to using a mouse • They tend to be used in more cramped conditions so their long-term use could lead to health problems such as RSI

Advantages of using a trackerball

• They are easier to use than a mouse if the user has wrist or finger problems • They allow faster navigation compared to a mouse • They are stationary as it is only the ball that moves

Disadvantages of using a trackerball

• The cost, as these are not normally included with a computer system • Time is needed for a user to get used to using them

Advantages of using a remote control

• The user can operate a device wirelessly from a short line of sight distance where a device's controls are difficult to reach ( e.g. a projector positioned on a ceiling) • Can control devices safely from a distance (e.g. a robot used to investigate a bomb) • Enables people with disabilities to operate devices from a distance

Disadvantages of using a remote control

• Typically uses infra-red signals which can be blocked by items in their path, so it may not operate • Needs batteries to operate and these need regular replacement • Small buttons can be pressed by mistake and this can alter the settings of the device and make it hard for the user to go back to the original state

Advantages of Joysticks

• They are ideal for quick movement • They can be used by disabled people because they can be operated by foot, mouth, etc.

Disadvantages of Joysticks

• Entering text is very slows as you have to select each letter individually • You have to purchase separately from a computer system

Advantages of touch screes

• They are very simple to use • They are easier to use while standing, compared to keyboards • They are ideal where space is limited such as on a smartphone, tablet etc. • They are tamper-proof, so other data cannot be entered that could corrupt the system • Enables faster selection of options than using a keyboard or a mouse (e.g. Kahoot)

Disadvantages of touch screens

• The screen can get very dirty and this can make items on the screen hard to see • There is danger that germs can be spread with many people touching the same screen (e.g. Covid) • On small screens the icons can be hard to see or select • They often cost more than input devices such as a keyboard

Uses of scanners

• Digitising photos / hard copy documents • Scanning text into word-processing software (OCR)

Advantages of scanners

• They can be used with OCR to scan and enter text into word processing software • They can be used to digitise old documents / photos, etc • They can be used with software to repair/improve old photos

Disadvantages of scanners

• They take up a lot of space • It can take a long time to digitise all the pages of a long document • the quality of the scanned item might be poor, depending on scanner resolution

Advantages of digital cameras

• No film to develop, so quicker to produce a photo • No need to use chemicals in developing films • A large number of photographs can be taken on the same subject and the best on can be chosen • The images are in a form that can be placed in documents, presentations and on websites • The digital images they produced are easily sent form place to place using phones, email attachments, etc. • Can use software to improve photos (e.g. to remove red-eye)

Disadvantages of digital cameras

• They are more expensive than traditional cameras. • Batteries need changing more often than with traditional cameras. • A photographer needs to have computer skills to use digital photographs correctly • A photograph may not be of as high quality as those produced using film. You are limited by the number of pixels that make up the image

What things does a microphone allow you to do

• You can instruct without hands (e.g. hands free phone in car) • You can take part in video conferencing • You can add narration to websites, presentations, and other multi-media products • You can input speech for VoIP (voice over internet protocol) and video conferencing systems

Advantages of Microphone

• Can be used by disabled people to input data/instruct • Can improve safety for car phones • They are relatively inexpensive • Cn be faster to speak instructions rather than type them

Disadvantages of Microphone

• Background noises can interfere and cause problems with voice recognition systems • Voice recognition is not completely accurate, so mistakes may occur • Sound files, when stored, take up a lot of disk space

Examples of what sensors measure

• Temperature • Pressure • Amount of light • Humidity • Pressure • Water Quality • Blood pressure • Breathing rate • Motion • and many more

Advantages of using sensors

• The readings are more accurate than those taken by humans • Readings are taken more frequently than by a human • They work when a human is not present, so costs are less • They can work in dangerous environments (e.g. mines, nuclear reactors, etc.)

Disadvantages of using sensors

• Purchase cost • Dirt and grease may affect performance

Advantages of graphics tablet

• Used in countries such as Japan and China where graphical characters are used instead of letters for words • It is more accurate to draw freehand on a tablet than to use a mouse to draw • The icons/buttons are on the graphics tablet rather than the screen, leaving more space for the design / drawing

Disadvantages of graphics tablet

• Specialist tablets are expensive • Requires more desk (as in table) space

Advantages of video camera

• Can capture both still and moving images • Easy to transfer video to the computer • Can store many images/video for editing later

Disadvantages of video cameras

• Can erode privacy as CCTV cameras are present in many public places • It is very difficult to produce good video without training • Editing is usually required to make a good video and this can be complicated and time consuming • Can be expensive to buy • The picture quality of the video is determined by the numbers of pixels used, (resolution) and this may be low

Uses of Webcams

• To conduct simple video conferencing • Allows parents to see their child at nursery while they are at work • To record video for the inclusion on websites • Allow people to view the traffic in local road systems • Allow people to view the actual weather in a place they are going on holidays

Advantages of Webcams

• They can be online constantly • They provide disabled people with the opportunity to stay in touch visually with friends and relatives without leaving their home • Can see the reactions of people when you are talking to them

Magnetic stripe reader uses

• Loyalty cards • Credit/Debit cards • Access to buildings/rooms

Advantages of Magnetic Stripe Readers

1. Data entry is very fast.

2. No possibility of errors.

3. Stripes on cards aren't affected by water and it is hard to damage them.

4. Cant be read by eye so data is safe.

Disadvantages of Magnetic Stripe Readers

• Small amount of data can be stored • Easily damaged by magnetic fields • Can be duplicated easily (card cloning) • Card fraud • Cannot be read at a distance, have to be swiped

Advantages of chip readers and PIN pads

• Reduce fraud as PIN has to be entered • Chips are harder to copy compared to magnetic stripe • Higher storage capacity than magnetic stripe • Less likely to be damaged than magnetic stripe

Disadvantages of chip readers and PIN pads

• Not all countries can use chip and PIN • People might forget their PIN • Other people might observe your pin (shoulder surfing)

RFID Tags Uses

• Stock control • Cattle can be tagged • Car park season ticket • Libraries - bar code replacement • Automated border control gates

Advantages of RFID tags

• Contact not required for reader to detect • More data compared to bar codes

Disadvantages of RFID tags

• Reader and tags are expensive • Personal info on tag can be stolen from a distance, identity theft, etc.

Advantages of Magnetic Ink Character Recognition (MICR)

• 100% Accuracy • Difficult to forge (cheques, etc. due to magnetic ink) • Can be read easily (fold, crumple proof as only magnetic ink is read) • High speed reading

Disadvantages of Magnetic Ink Character Recognition (MICR)

• High speed magnetic ink readers are expensive

Advantages of OMR (Optical Mark Reader)

• Only need 1 computer and one OMR reader (less expensive) • Almost 100% accuracy if forms filled correctly • Very fast

Disadvantages of OMR (Optical Mark Reader)

• Only suitable for capturing certain data (MCQ's) • Incorrectly filled forms could lead to high rejection rates • Folded paper may jam the machine

Uses of OMR

• Voting forms • Lottery tickets • Tests/assessments • School/college attendance registers

Advantages of Optical Character Reader (OCR)

• Faster way of inputting text than typing • Avoids RSI from typing • Can recognise handwriting • Reduces typing errors

Disadvantages of Optical Character Reader (OCR)

• Text needs to be clearly typed/written • Incorrectly filled forms rejected

Uses of Barcode

• itemised customer receipts • Stock control • Tracking parcels • Recording books in a library • Luggage labelling at airports

Information stored in a barcode

• Country of origin • Manufacturer • Product name • Price • Other

Advantages of barcode input

• Faster than typing in numbers • Greater accuracy than typing • Can be read from a distance using hand-held scanner • Can record barcode time and date • Prices can be changed by altering shop's database - no need to replace barcodes

Disadvantages of barcode input

• Barcodes can be damaged and become unreadable • Laser scanners can be expensive • Limited amount of data can be stored • Computers and networks must be at each point where barcode may be read (expensive)

Advantages of CRT monitors (Cathode Ray Tube)

• Good for when several people are viewing the screen, due to wide angle of viewing

Disadvantages of CRT monitors (Cathode Ray Tube)

• Bulky and take up lots of desk space • Generate a lot of heat, and can heat up rooms in the summer • Glare on the screen can be a problem • Much heavier, dangerous when moving • Flicker can cause headaches/eyesight problems

Advantages of TFT/LCD monitors (thin film transistor / liquid crystal display)

• Very light (used in laptops) • Thin • Cheaper to run - less power used • Can be easily positioned • Do not get hot • Do not create glare - less likely to cause eye strain/headaches • Much less radiation than CRT • Ideal when only one person viewing the screen

Disadvantages of TFT/LCD monitors (thin film transistor / liquid crystal display)

• Not easy to repair • Usually cheaper to replace them than to get it fixed, which is not environmentally friendly • Narrow viewing angle

IPS Monitor

In-plane switching monitor Generally used by creative professionals (professional graphics artists)

Advantages of IPS monitor (in plane switching)

• Wider viewing angle • Much thinner than TFT so take up less desk space • Less glare than CRT monitors • Can be used in brightly lit rooms (less glare) • More energy efficient than CRT monitor

Disadvantages of IPS monitor (in plane switching)

• Not as energy efficient as LED monitor • Not as good when used in dimly lit room • Worse graduating shades of color than LED monitor

LED monitor

A thinner, lighter, and more energy-efficient type of LCD monitor that is lit by a grid of tiny electronic lights called light emitting diodes.

Advantages of LED Monitors

• Thinner than CRT monitors • Same thickness as LCD monitors • Lighter than CRT monitors • Energy savings compared to CRT and LCD monitors • Better picture quality

Disadvantages of LED Monitors

• More expensive than LCD monitors • If you sit off centre, visibility is poor (narrow viewing angle)

Laser Printer

A type of printer mainly used by businesses and organisations because of their high speed / PPM (pages per minute). These printers are usually networked with other printers, like at OFS. Most laser printers print in black and white. You can buy a color laser printer, but they are relatively expensive.