More revision notes Flashcards
What are the components of a computer?
Processor Motherboard RAM memory Sound card Graphics card Optical Drive Hard Drive
What are the physical devices that make up the computer called?
Hardware
What are the computer programs, operating systems, utilities called?
software
What is the processor?
The “brain” of the computer, does all the calculations.
What is the motherboard?
The central circuit board of the computer. All the hardware has to connect to it.
What is RAM memory.
The “working memory” of the computer, this stores instructions/data before it is sent to the processor. IT is VOLATILE memory.
What is the sound card?
This sends sound to the speakers.
What is the graphics card?
This is a hardware processor that creates the images and sends them to the screen
What is an optical drive?
CD or DVD drive
What is the hard drive?
The storage area of the computer, where you save software and data.
Why should you uninstall software that is no longer needed, rather than just deleting?
Deleting is likely to only remove part of the program, this can cause machine crashes.
What is input?
Entering data on to a computer system.
What is an input device?
Any hardware used to enter data.
What is OCR?
Optical character reader (or recognition)
What is OMR?
Optical mark reader.
What is a barcode reader?
Any device for reading barcodes.
What does an OCR do?
Scans in writing and attempts to process it to make an editable text document. Being used on print as well, to put old books online.
What does an OMR do?
Looks for specific marks on the page, eg lines, crosses, Popular for multiple choice exams.
What does a barcode reader do?
It reads barcodes.
What is the advantage of OCR?
It can be much quicker than typing.
What is the advantage of OMR?
Faster than typing, more accurate.
What is the advantage of barcode?
Very good at identifying a specific item.
What is the disadvantage of OCR?
Handwriting may be hard to read; tries to read coffee stain on old book.
What is the disadvantage of OMR?
A lot of effort to set up - specific input forms need to be devised, programs adjusted to read in the right position.
What is the disadvantage of barcodes?
Have to be printed on the item in the first place. Use really limited only to identification.
What are the advantages/disadvantages of voice recognition?
Adv:
Faster than typing
No training required
Dis:
Takes time to set up
Background noise causes inaccuracy
What are biometrics?
Using human physical characteristics to give system security - eg retina recognition, fingerprint recognition.
What are the advantages of inkjet printers versus lasers?
Inkjet:
Printer cheap to buy, but ink is expensive
Slower than laser, better quality
Ink smudges, but quiet to print
Ink available in colour packs
Laser:
Faster than laser, more expensive to buy
Ink lasts longer, lower quality than inkjet
Very reliable, great for offices.
Name some other output devices?
Projectors
Speakers
Robot Arms
What is primary storage?
The memory that the computer uses to store the data that it needs to run.
What does RAM stand for?
Random Access Memory
What does ROM stand for?
Read Only Memory
What is ROM used for?
Permanent computer instructions.
What is the printer buffer?
Memory built into the printer to hold the document that it is printing/ about to print (printer queue).
What is secondary storage?
Backing storage, anywhere that you save documents and programs.
What is the most common secondary storage device?
The hard disk. Can be internal or external. A magnetic storage device.
Why would you use a hard disk to store data?
Very high transfer rate
Very high storage capacity (terabytes)
But
Moving parts mean that they break easily
Why would you use magnetic tape to store data?
It is very cheap.
Extra volumes are easy to add
But - slow transfer rate.
Why would you use flash USB memory sticks?
Cheap, lightweight
No moving parts, so reliable
Easily lost
Small capacity
Why would you use a flash memory card?
Used in camera or phone
No moving parts
Slow transfer rate
Why would you use a Flash solid state hard drive?
Very fast transfer rate No moving parts, so reliable but Expensive Low capacity
Why would you use optical drives?
Very cheap
Slow transfer rate
Low capacity
How much can a CD hold?
700mb
How much can a dvd hold?
4gb
What is meant by volatile memory?
When the computer turns off, the memory is lost
What is meant by non-volatile memory
Data is kept even when the computer turns off
What is meant by a peer to peer network?
A network where every computer is linked to every other computer, directly.
What is meant by a client-server network?
A central “server” is linked to all computers,
What are the advantages of peer to peer networks?
Easy to set up if there are less than 10 pcs;
if one cable breaks then the other links still work.
What are the disadvantages of peer to peer networks?
Complicated to set up if lots of PCs
Software has to be on every machine
Can only access your files on your pc
What are the advantages of client-server networks?
Central server is very powerful
Software on the central server can be shared everywhere
You can access all your files from any pc
What are the disadvantages of client server networks?
If the server breaks, nothing works
Expensive to set up as the server is expensive
What is a LAN?
Local area network
When would you use a LAN?
Small geographical area, eg one building (school); uses cables or wifi; cheap to build and run;
share documents
What is a WAN
Wide area network
When would you use a WAN?
Eg International company
Underwater cables can be used
Expensive to build
the internet is a WAN
What is encryption?
Coding data before sending it so that it cannot be read by anyone who does not have the code.
What is the opposite of encryption?
Decryption
Name some communication methods
Smoke signals Carrier pigeon Mobile phones SMS (texting) Sat nav Instant messenger Message board Email Fax Chatroom VOIP Landline Letters/postal system
How could you connect to the internet?
Modem
Broadband
Satellite
Why do we no longer use modem very much?
Slow
Can’t use phone at the same time
Why do we use broadband to connect to the internet?
It is always on, faster than a modem, cheaper.
Why would we like to use satellite for connecting to the internet?
Fast, but expensive
What are the advantages of wifi?
No wires to trip over
Work in the local coffee shop/leisure centre
What are the disadvantages of wifi?
Wifi is easier for hackers;
not everywhere has wireless;
some people still worry about health risks
What is downloading?
Copying the file onto your computer. A download can be used many times, but have to wait for the download to finish.
What is streaming?
Playing the multimedia as it downloads, so if the network goes down you stop watching.
What is the systems life cycle?
Feasibility study Analysis Design Implementation Testing Training Evaluation and monitoring Maintenance
Systems life cycle.
What is the Feasibility study?
Can the project be completed on time? and on budget?
Systems life cycle.
What is the Analysis?
Identify how current system works;
Identify problems with current system
Identify what new system should do
Systems life cycle.
What is the Design?
Sketch the new system
Work out inputs, processes, outputs.
Design the tests
Systems life cycle.
What is the implementation?
Build the system
Systems life cycle.
What is the Testing?
Test the system, correct errors
Systems life cycle.
What is the Evaluation and monitoring?
Check the original requirements are met
Monitor over time to see how well the new system is working
Systems life cycle.
What is the Maintenance?
Upgrade the system to solve any issues/ minor bugs.
What types of test are there?
Normal data - does the system work with the normal data
Extreme data - does the system cope with the highest and lowest values that it will encounter.
Erroneous data - make sure that invalid data cannot get in.
What is GIGO?
Garbage in, garbage out - the system can only produce outputs that are as good as the inputs.
What is verification?
Checking the data is correct - eg typing the same thing twice, reading the paper and comparing to screen.
What is validation?
Presence check - must be filled in
Range check - value must be within limits
Look up list - value chosen from list
Format check - characters are in correct format
Length check - eg mobile number has 11 numbers
What must you consider when presenting to people?
Target audience - age what are their needs what do they know literacy level interest level disabilities
Why would you need to reduce file size?
Make space on storage device
Up/download faster
What do you call reducing the file size?
Compression. May lose quality.
What does an operating system do?
Provides a user interface so that user can tell the computer what is wanted
Manages memory allocation
Manages filestore
Manages user accounts
Manages connected hardware
Error handling
Recognises presence of new hardware
Pretends life is simple so the user is not frightened off
What is batch processing?
Saving up a load of processing to do it all in one go - eg payroll, or council tax bills, or letters allocating the new schools for year 6s.
What is real time processing?
Changing the data as you go. Eg banking - you need to know that Fred has taken out his £100 as otherwise he could overdraw; games
What is a GUI?
Graphical user interface
What makes up a GUI?
WIMP
Windows
Icons
Menus
Pointers
Give some examples of applications software:
Spreadsheet database word processing desktop publishing web design graphics
Gives some examples of common features that make applications software user friendly.
Undo Cut copy paste Wizard help files drag and drop find and replace zoom in/out printing adjust page orientation font size/colour bullet points
Features of word processing?
- Edit text
- Lists
- Indentation
- Alignment
- Paragraphing
- Headings
- Borders
- Page numbers
- Spelling check
- Grammar check
- Line spacing
- Tables
- Insert images
- Word Count
- Insert clip-art
Features of presentation software?
- Pre-made template
- Choose colour scheme
- Insert images
- Insert video
- Insert text
- Insert buttons
- Insert hyperlinks
- Add animation
- Add slide transition
Features of web design software?
- Edit text
- Insert images
- Insert video
- Hyperlinks
- Hotspots
- Navigation bars
- Interactive Forms
- Animation
- Visitor Number Counters
Festures Graphic design software?
- Fill colour
- Erase
- Pick colour
- Brush size
- Shading
- Draw lines
- Add layers
- Rotate images
- Crop images
What data does a spreadsheet understand?
Integers (whole numbers) Percentages Decimal places Currency Fractions Dates / times Text
How can you make a spreadsheet user friendly?
Borders Lock cells with formulae Macro navigation buttons Clear instructions Images / clip-art Create graphs and charts
What are the formulae on a spreadsheet?
Addition, Subtraction, Multiplication, Division
What are the functions on a spreadsheet?
Functions are more complicated calculations the Spreadsheet can perform:
Find the Average number from a list =average()
Find Maximum number from a list =max()
Find Minimum number from a list =min()
Add up a list of numbers =SUM()
Round a number up or down =round()
Round a number up =roundup
Count how many times something is in a list =count()
Lookup a value from another table (e.g. lookup what grade 60% is) =VLOOKUP()
What is the most useful feature of spreadsheets?
Can be used to model “what if”? eg - what if we only got 50 6th formers next year.
Database software definitions. Data
Raw facts and figures without meaning
Database software definitions. Information
Data that has been processed to give it meaning
Database software definitions. Field
An item of data (e.g. a Surname)
Database software definitions. Record
A collection of data about 1 person or thing (e.g. a student record will include ID, Name, Address, Contact details)
Database software definitions. table
Stores data about a group of similar things
Database software definitions. Form
A User Friendly way to input data into a table
Database software definitions. Key field
A field that has to have a unique number in it. E.g. ID no. Means you are able to tell the difference between two Mohammad Mohammads
Database software definitions. Query
A way of searching through tables to find what you are looking for
Database software definitions. Report
Displays the answers from a Query in a user friendly way
Features of web browsing software?
- Back button
- Forward button
- URL Address Bar
- Favourites
- History log
- Zoom in/out
What methods are there for finding information on the internet?
Key word searches (e.g. via Google)
Following links from a page of links (e.g. Wikipedia)
Type in the URL if you know it
What is an ISP?
These are companies that give you access to the internet and to email, but they charge you a fee. E.g. AOL, BT, Virgin Media…
What is phishing?
This is where fake websites are set up to look like official websites to trick you into giving the owners your log in details or credit card information. Usually a fake bank website or fake social media website
What are the email protocols?
POP (Post Office Protocol) These are the rules that tell a computer how to receive emails
SMTP (Simple Mail Transfer Protocol) These are the rules that tell a computer how to send emails
What are the features of email?
Carbon Copy (CC) Blind Carbon Copy (BCC) File Attachments Address Book Reply Forward Create a signature
What is a blog?
A website for people to provide commentary, personal thoughts, or news on a particular subject. It is like an online diary. People can usually comment on each article on it
What is a social networking site?
a website where users can communicate with friends and family, and share images and videos. E.g. Facebook, Twitter, Myspace
What are the advantages of a social networking site?
- Helps build communities
- Allows you to make friends
- Allows you to express your opinions
- Lets you see how friends and family are doing
- Easy to share photos and videos with friends/family
- Can be used to find out news and events
What are the disadvantages of a social networking site?
- If you do not set your privacy settings anyone may read your personal info
- Your images might be copied or stolen by strangers
- Cyber-bullying is unfortunately very common
- Paedophiles can set up fake accounts for grooming
- Someone may post something about you that you do not like
- You may encounter stalkers
- Rumours may be started and spread
- It is not always easy to set your privacy settings up correctly
- Easy to waste time on them
- You can become addicted to them
What is data logging?
When data taken by sensors is saved over a period of time for subsequent processing.
What is the advantage of data logging?
Readings are taken at exactly right time Humans not needed No human error Readings are accurate Readings can be taken quickly Can run 24/7 Can be situated in dangerous places (e.g. north pole)
What are the disadvantages of data logging?
Equipment can malfunction
Equipment is expensive
What is the Data Protection Act for?
A law to protect personal data from being misused.
What is the data subject?
The person the data relates to.
What is personal data?
Any data that can be identified as coming from a specific person.
Who is the information commissioner?
A Government worker who enforces the DPA.
What is the Personal Data Guardianship Code?
Simplified rules to make it easier for organisation to keep the law.
What are the eight DPA rules?
- Only be used for legal purposes
- Only be used for the reason it was collected 3. Not keep extra information not needed 4. Be accurate and up to date
- Not be kept longer than needed
- Kept secure
- Not transferred outside the EU
- Not break data subject’s human rights
What are the DPA exemptions?
Exemptions:
- Government can break the DPA to investigate Tax Fraud
- Police can break DPA to investigate crimes
- Doctors can break DPA for medical reasons
What does the computer misuse act say?
This makes it illegal to:
- Send viruses on purpose
- Use a work computer for an unauthorised purpose
- Hack into someone else’s computer (to make changes or just to read data)
- Commit fraud
- Copy programs illegally (copyright)
How does the Health and Safety at work Act apply to computer use?
Injuries caused by using computer: Repetitive strain injury back ache Eye strain Stress
How is industry changing because of IT?
Automated production lines:
Robots are replacing humans in the manufacturing process. E.g. robots build cars or furniture
More standard products:
New products are not very creative. E.g. smartphones are all very similar now
Automated stock control:
Computers can count stock levels and re-order things that are running out
Internet shopping: Shops can sell online now easily, so can close their high street shops
Creation of new industries: New jobs are created that didn’t exist 20 years ago. E.g. Website designers
Globalization: It is so easy and cheap to travel and communicate online now that businesses can find partners/suppliers abroad
How are businesses changing due to IT?
Businesses can be smaller
Computers can many of the jobs of humans so with less employees you can have smaller office space (cheaper)
- Fewer unskilled jobs + More skilled jobs
Robots replacing unskilled jobs (e.g. food production)
Technical jobs to look after robots have been created
Location doesn’t have be high street
Businesses can move to cheaper offices because they can sell online.
This is resulting in empty shops on high streets
More teleworking
Working from home is now easy, so parents can work easier without worrying about child card
People need to be re-trained to use technology
Businesses need to invest in training their staff to use the new technology.
This is time consuming, but necessary
What changes are there on actual jobs?
- Increased unemployment
- Training and retraining expected
- Teleworking
- Hot-desking
- Flexible hours
- Better job satisfaction
- Easier to do tasks
- Easier to monitor staff 9. Easier to work with others
- More blur between work & play
- Contactable at any time
What are unacceptable uses of IT?
EMAIL FLAMING Spam Theft/fraud Plagiarism Breaking copyright (images/text/video) Phishing Viruses
What about the disabled?
One very positive effect of ICT on society is accessibility Accessibility describes how it is easier for those with disabilities, or the elderly to use technology to make their lives better
You need to have opinions on:
DNA databases
Police database
Passport agency database
NHS
Think about expense
security
trust in the organisation
should they be funded by taxes?
What about privacy?
MI5 listening in to phone/internet browsing? CCTV? Speed cameras? Facial recognition on cctv? Government agency looking at cctv?
ICT and the environment?
Better control of systems - heating, lighting can be controlled better, save power
Sat nav - direct route saves fuel
Traffic management systems - cars keep moving, less pollution
Pollution monitoring
ICT and collaboration?
Sharing documents;
deadline monitoring;
teleworking
