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Computer EoY9 (1.4 (Types of Networks (Advantages (Security can be managed…

- - - - Security can be managed by the network manager. Virus Protection and patches shared centrally
      - Files can be accessed form any computer
      - Data only needs to be backed up on central sever
      - Updates and software applications can be distributed atomatically
      - Share resources easier
      - Can communicate with each other
    - - If one part of the network fails, the whole network could go down
      - Can be hacked and viruses easily spread
      - More expensive to setup and maintain
    - - Virtual Private Network - Not a physical network but a part of the internet which is en
    - - Wide Area Network - Collection of computers over a widegeographical area that are connected and managed centrally
    - - Local Area Network - Collection of computers over a small geographical area that are connected and managed centrally
  - - - Disadvantages
        
        Harder to keep track of files
        
        Less reliable
        
        Security Harder
        
        Backups and Updates harder
      - Advantages
        
        No dependence
        
        Cheap
        
        Easy to maintain
      - A cheaper network to set up as less hardware needs to be purchased
      - Peripherals on the network can be shared
      - Each computer on the network needs to be ,maintained separately
      - Computers are networked together
      - Most commonly found in a home or small office
    - - Disadvantage
        
        May become overloaded
        
        Server Dependent
        
        Requires Specialist
        
        Expensive
      - Advantages
        
        Very Reliable
        
        Keep track of files
        
        Security easier to manage
        
        Backups easier and Updates easier
      - Most commonly found in larger offices and orgaisations
      - Peripherals on the network can be shared
      - It has a central computer that provides all the services to the network
      - Files can be automatically backed-up to a central location from each computer
      - An expensive network to set up as more hardware needs to be purchased
  - - - Password are the most common way to prove your identity. They should be strong with a range of characters and should be changed regularly
    - - User access levels control parts of network different groups can access. High authority have higher access levels allowing them to see more sensitive data. They also have the ability to change people's access levels.
    - - The different types are WAP, WAP2 and WEP however this should not be used as it is weak
      - Encrypting data scrambles the data with a maths formula or "key" which turns the data into seemingly unrelated characters. Encrypted data is called Cipher text and un-encrypted is called plain text
- - - - These include SD cards, ROM Chips, Pen Drives
  - - - Because the RAM is faster than the Hardrive their is delay between the swapping. If the computer has to swap out to much, it will slow down and could crash all together. This is called Disk Thrashing
  - - - When the computer is turned on the BIOS or Basic Input Output System which runs a POST(Power On Self Test) check to see if the compute is healthy. If it is then the bootstrap program is loaded from ROM to RAM. The bootstrap locates the OS in the Hardrive and it is loaded into RAM. The OS takes over and finds the boot files. These include all the user customised options such as wallpaper
      - The memory is non-volatile so does not get lost when no power is running through it
  - - - It uses SRAM which is faster the DRAM and does not constantly need to be refreshed however it is more expensive and requires 6 times transistors and capacitors. It is the less type so you have less in a computer
    - - It uses DRAM which is slower the SRAM and constantly needs to be refreshed however it is cheaper and requires less transistors and capacitors. It is the more common type so you have more in a computer
    - - It is called Volatile Memory because when RAM loses power all the data is lost and cannot be retrieved
- - - - The Clock Speed describes how many FDE Cycles the CPU can complete
    - - The better the materials, the faster it will go
    - - More cores means how many FDE cycles the CPU can do at once
    - - The more cache means more data stored in high speed memory
    - - The word size describes how many bits the CPU can handle
- - - - Speed
        
        Fastest type of storage
      - Reliability
        
        It has a limited number of read and write cycles which limits its useful time, However the SS are usually very reliable.
      - Cost
        
        Most expensive
      - Capacity
        
        Medium Capacities
      - Portability
        
        Portable in small devices
      - Durability
        
        Very Durable as it has no moving parts
    - - Speed
        
        Slowest type unless in a internal hard drive
      - Reliability
        
        Great for archiving if well kept
      - Cost
        
        Cheapest type
      - Capacity
        
        Largest Capacity
      - Portability
        
        Not overly portable
      - Durability
        
        Very durable if treated correctly. Can be damaged by dropping or magnetic fields
    - - Speed
        
        Slower read times
      - Reliability
        
        Not very reliable
      - Cost
        
        Relatively Cheap
      - Capacity
        
        Decent Capacity
      - Portability
        
        Easy to distribute
      - Durability
        
        Easily scrached and damaged
  - - - Let'ts say a bool has 90,000 words and each word takes up 7 characters each character is 2 bytes. This means it would be 2x7x90,000 = 1,260,000 Bytes. Covert to = KB so divide by 1024 to get 1230 KB
      - For example one megabyte is equivalent to 1024 kilobyte
    - - 4 bit
    - - 8 bit