Independent Study: Assessment Revision

Independent Study: Assessment Revision

1. LAN and WAN

   • LAN
     • Local-Area-Network
     • Used for small geographical areas
     • Advantages
       • Cheaper than WAN
       • Safer than WAN
       • Faster than WAN
     • Uses ethernet technology
     • Disadvantages
       • High setup cost
       • Covers limited area
       • Vulnerable to security threats
   • WAN
     • Wide-Area-Network
     • Used for large geographical areas
     • Advantages
       • Increased privacy
       • Increased bandwidth
       • Lower chance of the network going down
     • Disadvantages
       • High setup costs
       • Security concerns
       • Maintenance issues
     • Uses telephone lines

2. Client-Server and Peer-to-Peer

   • Client-server
     • A type of network where clients access resources from a central computer
     • Advantages
       • All files are stored in a central location
       • Backups and network security is controlled centrally
       • Users can access shared data which is centrally controlled
     • Disadvantages
       • Expensive to purchase
       • Specialist staff, such as a network manager, is needed
       • If any part of the network fails a lot of disruption can occur
   • Peer-to-peer
     • A group of computers are linked together with equal responsibilities for processing data
     • Advantages
       • Easy file sharing
       • Cheaper than client server
       • Can share files quickly over far distances
     • Disadvantages
       • Backup has to be done on each computer
       • No control of access to data as there is no server
       • Easy remote access can lead to compromised systems

3. Binary conversion to hex

   • How to do it:
     • Take binary number
       • Divide the binary digits into groups of four (starting from right) for integer part and start from left for fraction part
         • Convert each group of four binary digits to one hexadecimal digit
   • Binary
     • Binary is, basically, the language that computers speak
   • Hex
     • Hex is modern, simple way of writing out binary

4. Count-controlled iteration

   • Repeatedly runs a section of code a fixed number of times

5. Logic errors, Syntax errors and data types

   • Logic errors
     • A logic error is an error in the way that you want the program the work. All of the code is fine and works but not in the ways that you want it to
   • Syntax errors
     • A syntax error is an error in the code itself, its language has been typed out wrong. This means that the code won't work at all.
   • Data types
     • Boolean
       • Boolean is used for storing two values. True and false
     • String
       • A string is a collection of characters to make a whole word. For example, "Hello" is a string
     • Integer
       • An integer is a whole number. For example, 4 is an integer
     • Real
       • A real is a decimal point. For example, 1.2 is a real
     • Character
       • A character is a single letter or a single key on the keyboard. For example, "F" is character