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Computer Science GCES AQA

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  1. Representing Algorithms Aqa
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  2. Efficiency Of Algorithms Aqa
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  3. Searching Algorithms Aqa
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  4. Sorting Algorithms Aqa
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  5. Data Types Aqa
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  6. Programming Concepts Aqa
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  7. Arithmetic Relational And Boolean Operations Aqa
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  8. Data Structures Aqa
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  9. String Manipulation Aqa
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  10. Random Number Generation Aqa
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  11. Structured Programming Aqa
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  12. Robust And Secure Programming Aqa
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  13. Number Bases Aqa
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  14. Converting Between Number Bases Aqa
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  15. Units Of Information Aqa
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  16. Hardware And Software Aqa
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  17. Boolean Logic Aqa
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  18. Programming Languages And Translators Aqa
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  19. Cpu Architecture Performance And Embedded Systems Aqa
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  20. Memory Aqa
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  21. Secondary Storage Aqa
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  22. Fundamentals Of Computer Networks Aqa
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  23. Fundamentals Of Cyber Security Aqa
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  24. Methods Of Preventing Cyber Security Threats Aqa
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  25. Relational Databases Aqa
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  26. Ethical Legal And Environmental Impacts Aqa
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Exam code:8525

Networks

What are the different types of networks?

  • A network is two of more devices connected together with the purpose of sharing resources

  • There are three main types of network

    • Local Area Network (LAN)

    • Wide Area Network (WAN)

    • Personal Area Network (PAN)

  • For the exam it is important to know the advantage and disadvantages of each type of network as well as the advantages and disadvantages of networks as a whole

What are the advantages of having a network?

  • Users can share resources such as printers and connection to the internet 

  • Users can access their files from any computer on the network

  • Communication can be made easier via email and social networks

  • Users can share files and folders easily such as central databases and spreadsheets

  • Servers can be used to provide centralised backups, updates and security

What are the disadvantages of having a network?

  • There is an increased security risk to data 

  • Malicious software can infiltrate the network and render it unusable

  • Servers and switches can provide a central point of failure, resulting in users not being able to complete tasks using their computer

  • Factors can impact the performance of the network such as the number of users and data on the network at one time

Types of Network

What is a LAN?

  • A local area network (LAN) is a network which has a small geographical area (under 1 mile)

  • All of the hardware is owned by the company/organisation/household using it

  • LANs will use unshielded twisted pair (UTP) cable, fibre optic cable or wireless connections (Wi-Fi)

lan

What is a WAN?

  • A wide area network (WAN) is a network which has a large geographical area (over 1 mile)

  • They are a collection of LANs joined together

  • The computers on a WAN are connected via routers

  • The hardware used to connect the networks together is not all owned by the company/organisation/household using it.

  • Telephone lines owned by telecommunication companies are an example

  • WANs will use fibre optic cable, telephone lines and satellite to connect the LANs together

wan

What is a PAN?

  • A personal area network (PAN) is a network that is used for transmission of data between devices in close proximity

  • A PAN has a very short range (10 metres)

  • Bluetooth is the most widely used PAN

  • Typical examples of devices which make use of a PAN are:

    • Wireless headphones

    • Mobile phones

    • Tablet

    • Laptop etc.

What is Bluetooth?

bluetooth
  • Bluetooth is another common standard for wireless networks

  • Bluetooth is common in most homes and offices to connect devices such as headphones, controllers, keyboards & mice

  • Bluetooth is used typically for a direct connection between two devices

Worked Example

(a) State one wireless method used to connect devices on a Personal Area Network (PAN) [1]

(b) A travel agent has offices in two sites that are 10 miles apart. Describe two differences between a Local Area Network (LAN) and a Wide Area Network (WAN) [2]

Answers

  • (a) Bluetooth

  • (b) Max two marks from

  • LANs cover relatively small geographical areas // WANs usually cover a wide geographic area

  • LANs often owned and controlled/managed by a single person/organisation // WANs often under collective/distributed ownership

  • WANs are (usually) several LANs connected together

  • WANs (usually) have a much larger number of devices/users than LANs

  • LAN has a lower latency // WAN has higher latency

  • WANs are (usually) slower than LANs

  • The cost-per-byte for transmission is much higher on a WAN

  • LANs and WANs use different protocols

Responses

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