ICT Short Course Key Revision notes

A list of key terms
Chapter 1
Hardware: the physical objects that make up a computer system, such as computers, monitors and printers.
Software: the stuff that makes up a computer that you can’t touch.
Examples of application software: Word processor: Microsoft Word, OpenOffice Writer. Desktop publishing software: Microsoft Publisher, Adobe InDesign, Serif Pageplus. Presentation software: Microsoft PowerPoint, OpenOffice Impress, StarImpress, GoogleDocs Presentation. Interactive presentation: affected by user input. Graphics software: Photoshop, GIMP, Imagine!, Ultimate Paint. Web-design software: Adobe Dreamweaver, Serif Webplus. Filter: in graphics software, it changes the appearance of an image (e.g. blur, pixelate, brush strokes).
Input: data entered into a system. Examples of inputs are bar-codes scanned in a supermarket or key strokes entered by a typist.
Output: the action that occurs after an input has been processed. For example, the name and price of an item is displayed on a monitor following a bar-code scan.
Processing: turning the input into a useful form. For example, comparing bar-code data with a database to analyse which item it corresponds to.
Stored: information is kept for later use, for example information on the stock levels after the item has been scanned.
Devices: pieces of hardware. For example, a monitor is an output device.
Microprocessor: a silicon chip that contains a central processing unit, which acts as the brain of the computer.
CPU: central processing unit; the part of the computer that does most of the data processing.
Operating systems software: controls and manages the computer. Examples are Windows, Mac OS and Linux.
Applications software: computer programs that are designed to carry out specific tasks.
ROM: read-only memory. It contains instructions that are built in during manufacture. When the computer boots up it loads instructions from ROM but the computer cannot write data to it.
RAM: random-access memory. This is used when the computer is operating and it holds programs and data while the computer is switched on. As soon as the power is turned off, data held in RAM is lost. Increasing the amount of RAM on a computer helps improve its performance.
Boots up: when the computer is switched on, it automatically performs a set of processes to allow the computer to be used.
Examples of devices: input: keyboard, mouse, microphone, digital camera, touch screen, magnetic stripes, sensors, automatic data-capture devices, bar code reader, OMR (optical mark recognition (11+ papers)), OCR (optical character recognition (passport forms).
Examples of devices: output: monitor, speaker, printer (laser (more expensive to buy, cheaper to run) and inkjet (cheaper to buy, more expensive to run), digital projector, plotter (expensive, for architects and engineering companies), control devices.
User interface: the way the user interacts with the computer – input and output devices as well as the screen display
GUI: graphical user interface with windows, icons, menus and pointers
Hyperlinks: links to other web pages or files, usually accessed by clicking on a word or image
Resolution: measures how many dots of colour and image is made up of. This can apply to a bitmap image, a display on a monitor or a printed page. High resolution (more dots per inch) gives better quality.
Menu user interface: an interface where the user chooses from a restricted list of options.
File path: an address for the file that specifies exactly which folder it is stored in.
File extension: a code that defines the type of file. At the end of the file name there is a dot plus the extension. Some extensions: .doc – word processor, .xls – spreadsheet, .jpg - image, .png – image.
You can upload a file to a web service to overcome attachment size problems or you can compress files. A compression program is needed by the sender and the receiver. It makes file sizes smaller in order to transfer them more quickly.
Encoding: replacing data with a code which shortens in (for example replacing male with M).
Corrupt: the data in a file is unreadable. This can happen if the data is changed or damaged in some way so that it cannot be loaded by the original software.
Buffers: temporary storage areas in the printer that hold the data waiting to be printed.
Actuators: devices that perform an action in response to a signal from a computer.
Backups: copies of data stored in case the original is stolen or becomes corrupt.
WWW: World Wide Web: a system of internet servers that support a collection of web pages on the internet which hyperlink to each other
LAN: local area network: a network connecting computers in the same area/room/buildings.
WAN: wide area network: a network that covers a geographical area larger than a signal building, it may be national or global.
SMS: short message service: a system for sending text messages on a mobile phone.
Modem: electronic devise used to connect computers via a telephone line. It converts digital data to analogue and vice versa.
Digital signals: signals that take only two values, off or on, in binary code.
Analogue signals: electrical signals that vary continuously.
Bandwidth: the rate at which data can be transferred. If bandwidth is too low, data is transferred very slowly.
Dongle: a small piece of hardware that connects to a computer’s USB port. It allows a computer user to use certain pieces of software. Most wireless broadband services use dongles as part of their modem devices.
SIM card: subscriber identity module card; a small electronic card inserted into a mobile phone that provides a unique ID for that phone.
Integrated entertainment systems: systems that combine a range of devices offering visual, musical, video, audio and gaming entertainment.
Chapter 2
Feasibility study: an investigation to decide whether it is worth proceeding with a project or not.
Client: the person who wants the new system.
User: the person who will actually use the system.
Closed questions: questions where the answers are limited and the response has to be one of the options given.
Open questions: questions where the person can give any answer at all.
Sample size: the number of questionnaires that are given out.
Systems life cycle: design – implementation – systems testing – user training and documentation – evaluation – monitoring and maintenance – feasibility study – systems analysis (and back to design!). ADITE: analysis design implementation testing evaluation.
Validation: ensures that data is sensible in the context in which it is being used.
Verification: checking a completed record against the written form.
Performance criteria: statements of what levels of performance the finished product should have.
Patch: a piece of code that updates a software package. Patches are often downloaded from the software company’s website.
Chapter 3
Task specific: applications software is task specific. It has a number of features that are designed to carry out particular jobs.
Generic features: features that appear in many different types of applications software.
Open source software: software code is freely available for people to use, copy and edit. Pros: free, rapid addition of new features, fast fixing of any bugs, can be customised for applications.
Proprietary software: software that costs to use, no access to the coding and no permission to edit or change it. Pros: good follow-up service, automatic updates, the company has to ensure it won’t harm computers.
Flash: app. software that adds animation/interactivity to web pages.
Hotspots: area on a page that changes when mouse hovers over/clicks on (can be invisible).
WYSIWYG: what you see is what you get – can look at something similar to end result while editing.
Play list: list of songs selected from a library.
Streaming: multimedia content is played to end user whilst it is being downloaded.
Import: transfer a file created in one app. software to the currently open one.
Export: prep a file currently open for use by other softwares.
Chapter 4
Spreadsheets: documents that store data in a grid of rows and columns – analysed using formulae and calculations.
Databases: collections of data/records stored in tables.
Information: data with meaning.
Data: raw figures or words with no meaning.
Data types: descriptions of types of data being stored in a cell, e.g. text, numbers, dates.
Number formats: description of how data in cell is displayed (no. of d.p.).
Functions: math. operations performed on value in cell (SUM, AVERAGE).
SUM: adds all numbers in range together.
MIN: lowest value in range.
MAX: largest value in range.
AVERAGE: mean of range.
IF: returns different value if answer is yes or no.
Relative cell reference: program does not store address of cell but stores it relative to cell containing formula (E11).
Absolute cell reference: actual location of cell is stored ($E$11).
Flat file database: one table of data.
Fields: column headings in table.
Data redundancy: same data stored more than once in a table aka data duplication.
Relational database: two or more tables linked.
Key field: aka primary key, field that uniquely identifies each record.
Chapter 5
Web browser: internet browser: software used to view web pages.
Codes: AND –contains both criteria. NOT – or – doesn’t contain one e.g. MP3s not iPods. OR –gets either one or other. “” –exact phrase.
*wildcard search – cook* words beginning with cook e.g. cooking, cooker.
Internet service provider ISP: company providing internet access.
CC: carbon copy + email address - sends to them (doesn’t affect them but they should know of it)
Bcc: blind carbon copy + email address - sends to them but they don’t know email address of sender.
Junk mail – spam, sent in bulk, to users who did not request or opt in. Messages generally seen by provider as spam and sent to junk folder.
Spam filters: block spammers and look for key words. This can mislabel.
Instant messaging: real-time text convo between 2 or 2+ people all online.
Web log: blog: people write about something/recent events.
Social networking: contacting other people/friends to arrange to meet or find out about interest. Good: contact people, meet similar people, people who don’t live near. Bad: identity theft, people lying about themselves, meeting people who are not what they appear to be.
Plug-in: small software application downloaded via an internet browser, it enables a specific function e.g. Flash.
Forum: message board: online discussion website consisting of user-generate content.
Podcast: audio and video files downloaded from internet, normally updated daily/weekly. Good: you can subscribe, free/pay for.
Chapter 6
Logging period: total length of time data is being recorded.
Computerised pros: 24/7/365, cheaper, accurate + consistent – no human error, small logging intervals, can be placed in places inaccessible to humans, immediate analysis – can take action if required, automatically present reading as graph/table. Disadvantages: buying/set up expensive, faulty sensors not noticed, if it fails data will not be taken and previous data may be lost.
Logging interval: length of time between recordings of each measurement.
Calibration: accuracy of sensor checked against known scale.
Control software: software to program robots/devices with instructions, can act remotely/automatically (traffic lights), examples; StarLogo (simple), Flowol (complex).
Turtle: small robot, simple programmed instructions.
Feedback: the way output influences input e.g. heater switching on affects temp. input.
Autopilot control feedback loop: can fly better and more accurately than humans – landings in zero visibility, smoother flights. Collects current position and status using sensors. Human pilot sets the course. Autopilot compares the two and adjusts plane to keep it on course.
Laptop: personal computer: PC: computer small enough to carry around with built in keyboard, mouse and screen.
Smart mobile phones: smart phones: PDAs: palmtops: phones that offer features found on PCs such as email, internet and app. software. Often have: TV, satellite navigation (satnav), electronic organiser, telephone, and computer abilities.
Wireless application protocol: WAPL a tech that enables mobile phone users to view a phone friendly version of websites.
Chapter 7
Data Protection Act 1998 (only applies to individuals) protects privacy of people whose data is held (data subjects) users of this data are data users. It must ne: fairly and lawfully processed, processed for limited purposes, adequate, relevant and not excessive, accurate and up-to-date, not kept longer than necessary, processed in line with your rights secure, not transferred transnationally without adequate protection. As a subject you can: see what data is held, correct if inaccurate, ask the organisation not to process certain information if it might cause you damage or distress, refuse to have your data used for direct marketing (junk mail), complain to the Information Commissioner if person in charge of keeping the rules hasn’t, claim compensation through courts if you have been damaged by breaking of rules.
Exemptions to data act: national security at risk, must be available to public, needed for personal user within families, needed to prevent/detect crime, needed to collect taxes.
Data protection act 1998: a law to protect privacy of personal data.
Data subject: people about whom data is stored.
Data user: people or organisation that stores personal data.
Information commissioner: government department enforces DPA.
Data controller: person in organisation responsible for following DPA rules.
Exemptions: situations were DPA rules to do not apply.
Viruses: pieces of computer code than can reproduce by copying themselves to other files. Can cause damage to stored data or stop programs running properly.
Hacking: accessing a computer system you are not authorised to use. Offence under Computer misuse act 1990.
Intellectual property: ideas or creations such as music or software that can be protected by copyright.
Software licence: a legal agreement stating how a piece of software may be installed and used.
Plagiarism: copying a piece of intellectual property from someone else and presenting it as your own work.
Copyright: a legal right given to someone who creates intellectual property that means other people cannot use it without the owner’s permission.
Peer-to-peer site: a P2P site: people upload music/video for download, usually illegal.
CAD: computer-aided design: uses a computer to produce drawing of a product. May also be used for automatic calculation of weight, strengths, etc.
CAM: computer-assisted manufacture: often uses output from CAD packages. Uses computers to control manufacturing tools or assemble.
E-commerce: uses internet for commercial tasks. Pros: buy anytime, more choice, comparison easy, no travelling costs, business does not need a high-street shop. Cons: computer/internet access required, goods may be damaged/incorrect, have to be at home to receive, cannot feel/see goods.
Teleworking: working from home using a networked computer rather than travelling to a place of work each day.
National databases: DNA, National identity card.
CCTV: closed-circuit television: an unmanned, remotely mounted video camera system that transmits live images back to a screen where developments can be monitored and recorded.
Chapter 8
RSI: repetitive strain injury: causes painful joints in wrists or fingers aka upper limb disorder, caused by using a computer for a long time (new research suggests it’s more the overuse of the mouse than the keyboard).
Eye problems: looking at a computer for too long can cause eye strain or headaches, worse if screen is not clean and suffers from glare from reflected light.
Stress: in ICT jobs, people are monitored more closely. In calls centres, operators are expected to answer quickly and conversations are recorded. If targets are set too high, operators may work during breaks to avoid falling behind. Some stress is acceptable but if stress levels are too high they can become health risks.
Back and neck problems: sitting still for long periods of time can cause/aggravate back/neck problems. To counter: well-designed adjustable chair, eyes level with top of monitor, feet resting on floor/foot rest, monitor that can tilt/swivel, enough workspace for paper and other equipment to be placed.
Tripping: many offices not designed for lots of equipment – lots of cables.
Heat: offices with too many computers can overheat.
Fire protection methods.
Hygiene: must be clean,
Lighting: minimal eye damage by effective placement.
UPS: uninterruptible power supply – protects computer if power fails until can be shut down safely, protects against voltage surges.
Avatar: picture that represents you online (safer than real picture).
Grooming: criminal offence where a young person’s confidence is built online which can lead to abuse if a face-to-face meeting is arranged.
Cyber bullying: using computers and mobile phones in ways that make another person unhappy or uncomfortable.
Chain e-mails: emails that encourage you to make lots of copies and send them to all your contacts. May include threats if you break the chain.
Flaming e-mails: contain angry or abusive messages.
Firewall: software or hardware that limits data that can be sent to or from a computer preventing unauthorised access.
User names: unique names used to access networks.
Passwords: combos of letters and numbers that should be kept secret as they control access to your user name.
Encryption: scrambling data to make it secure. Users must have the key to the code to read the data.
Uniform resource locator (url): another name for a web address.
Levels of access: the rights you have over network files. No access: cannot open file, may not be able to see it at all. Read only: can open file, perhaps save a copy, but cannot edit original. Read/write: can read file and make changes but cannot delete file. Full access: can do anything to file.
PIN: personal identification number: numeric password often used to access ATMs or bank accounts.
ATM: automated teller machine: allows bank customers to check their accounts, withdraw and deposition money. aka cashpoints or hole-in-the-wall machines.
Biometric: uses human characteristics such as fingerprints as identification methods.
Internet fraud: general term for using the internet to steal money by obtaining banking or credit card details.
Phishing: sending emails that pretend to be someone from an organisation that handles financial transactions, asking users to click on a web link and enter banking info such as passwords.
Identity theft: gather personal info that can be used to identify someone then obtaining money or goods by pretending to be them.
Spyware: software downloaded onto a computer without the owner’s knowledge or permission. Sends data from the owners computer.
AUPs: acceptable use policies: agreements that set out what users are allowed to do on an organisation’s computer system.