Computer science

• what does the AND gate look like


   the output is high if all the inputs are high

  
• what does the OR gate look like


  the outputs is high if one or more of the inputs are high

  
• what does the NOT gate look like


  whatever the input is the output is always the opposite

  
• logic gate


  electronic device which either produces or does not produce an output depending on the inputs it receives and the logic rule it is designed to apply
• decomposition 


  breaking down parts of a big problem into smaller parts
• pattern recognition


  It involves finding the similarities or patterns among small, decomposed problems 
• abstractionFocusing on what'simportant, ignoring what'sunnecessary.
• Algorithm


  An algorithm is a plan, a set of step-by-step instructions to solve a problem
• Selection


   a question is asked, and depending on the answer, the program takes one of two courses of action.
• Iteration


  when a task is repeated for a set amount of times until there is a required outcome
• sequence


  set of tasks that are performed at one time
• what are the data types?

  1. Integer
  2. Real- decimal places
  3. Boolean- true or false options
  4. character- letter, number or symbol
  5. string- eg ."hello"
• loops


  repeat a sequence of code for a certain number of times
• domain names

  • .uk
• different types of loops

  • condition- the number of iterations is unknown before the loop starts. They stop when certain conditions are met eg WHILE loop. Count- the iterations continue for a fixed number of times
• packets


  messages in small amounts of data
• IP address


  made up of 4 groups of numbers between 0-25
• bandwidth


  amount of data that can be passed through the transmission media per second
• broadband


  A high-speed connection to the internet that has superseded the use of dial-up connections
• how many bits are there in a byte


  8 bits
• Wide Area Networks (WAN)


  cover a large area uses cables, radio waves to connects
• Local area network (LAN)


  cover a small area usually operate on a single site
• Network Interface card (NIC) 


  essential to connect to a network, can be wired or wireless
• what are the network topologies

  • Star
  • Ring
  • Bus
• Star network


  used to connect to a LAN

  
• Bus network


  terminator- absorbs signals

  
• ring network


  terminal

  
• system life cycle


  series of stages that are worked during a development of a new computer system

  
• features of html

  • describes the structure of a web page
  • contains a series of elements
  • defined by a start tag, some content and an end tag
  • the html element is everything from the start tag to the end tag
• what is css


  it is cascading style sheets that defines the style and layout of web pages
• why <div> tags


  create seperate sections in the html document
• inline css


  styles directly within html tags using the style attribute
• internal css


  styles within a <style> tag
• external css


  styles written in seperate .css styles linked to the HTML document
• advantages of external css

  • consistency across pages
  • easier maintenance
  • performance benefits
  • cleaner html
• floating


  pushes an image to the right