The Online world

1. Firewall

1. Anti-virus software

1. Privacy

1. Insurance + cloud storage

1. Physical barriers

Nota:

• bits are transmitted one at a time over a single wire

1. Longer range
2. Slow speed
3. Cheaper

Nota:

• a number of bits are transmitted over an equal number of wires/channels, this allows for a whole byte to be transmitted

1. Higher speed
2. More expensive
3. Short range

1. Simplex transmission

   Nota:

   • Sends data in one direction only
2. Half-duplex transmission

   Nota:

   • Data can be sent in both directions, but only one way at a time, like walkie-talkies
3. Full Duplex transmission

   Nota:

   • Allows two way transmission at the same time

1. A serial transmission method, maximum speed of 480 mbps

1. POP3
2. SMTP
3. IMAP

   Nota:

   • Allows the user to read eMail without downloading them

1. iTunes

1. Some free, some not
2. DropBox, Justcloud, microsoft skydrive
3. Security, you have to trust the people that own the cloud
4. Network of servers, each with different jobs
5. Only pay for the storage you use
6. Available anywhere with an internet connection
7. May not be using up-to-date software
8. May not be a reliable network

1. Instant messaging

1. Stock exchange

1. e-voting

1. e-voting

1. Online tutorials

1. Moodle

1. Stocks

1. eBay, Amazon

1. Video conferencing

1. Games

1. FaceBook

1. Skype

1. UTP/STP
   1. Cheap
   2. Slow
2. Fiber Optic
   1. Very Fast
   2. Expensive
3. Coxial
   1. Fast
   2. Interference

1. Infrared
   1. Direct line of sight needed
   2. Reliable
2. Microwave
   1. Short range
   2. Does not diminish
3. Satellite
   1. Expensive
   2. Huge Bandwidth

1. The system that runs the data base, and sorts through the data
2. SQL
   1. DDL
      1. Used to define the database structure
   2. DML
      1. Used to add, delete, change and query
   3. The high level language used to make the DBMS

1. Used to store things that an entire network can access
2. Search engines
   1. Collections of webpages in a database
      1. The web is a completely unorganised pile of data
   2. Websites are found with keywords using a bot called a 'spider'

1. Every time someone clicks on the ad, the company pays the website money

1. Figure out the target market, put ads on websites they would go on

1. Advertisments on search engines that appear when someone searches certain keywords

1. Voice over internet protocal

1. Radio frequency identification
   1. Uses radio waves to transmit data
      1. Used in Ubiquitous computing
         1. Computing everywhere
         2. Used to measure stock

1. Point of presence
   1. Access point to the internet

1. Network access point
   1. Interchange between two networks

1. Internet protocal
   1. The way information is passed across the internet

1. Transmission control protocal
   1. How user information is passed to the IP to be transferred across the internet

1. File transfer protocal
   1. Allows transfers of files between computers

1. Internet service provider
   1. Companies that provide internet access

1. Hyper-text markup language
   1. A computer language used to create webpages

1. Uniform resource locator
   1. a webpage address

1. Simple Mail transfer protocal
   1. The standard use of email

1. Post office protocal 3
   1. Used to retreve emails from an email server

1. Internet message access protocal
   1. The other email protocol, emails reside on an email server and never reach the computer

1. Unshielded twisted pair/sheilded twisted pair
   1. Cables that help the transmission of data

1. Universal serial bus
   1. a high speed connection standard that is commonly used

1. Coder/decoder
   1. Turns a analogue voice into a digital signal, sends it over the internet as packets and decodes it at the end

1. A set of rules which govern the behavior of people on the internet

1. Server side processing is when scripts are used that reside on a different server over the internet
   1. ADVANTAGES
      1. EFFICEINTCY
         1. Complex code can be ran faster, as it does not have to be downloaded onto the user's computer
      2. BROWSER INDEPENDANT
         1. This means the code can be run on any browser
      3. SPEED
         1. Performance is only affected by the speed of the web server and the download speed of your computer
   2. DISADVANTAGES
      1. SECURITY
         1. The exchange of data over the network may present security risks
      2. OVERLOADING
         1. The server needs to be able to cope with large amounts of data

1. This is used to create interactivity on webpages, with the script being downloaded with the webpage
   1. ADVANTAGES
      1. SPEED
         1. The interaction is faster once the code has been downloaded
      2. SECURITY
         1. It is more secure than server side because everything happens on the downloaded page, rather than coming from the web browser, which could cause security problems or corruption
   2. DISADVANTAGES
      1. BROWSER SPECIFIC
         1. Not all browsers work the same, so different codes are needed for each browser
      2. COMPUTER SPEED
         1. Because the web page is downloaded onto your computer, any interactions are affected by your computer speed