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EnglandComputer Science

4.8 Communication and networking

5 dot points across 5 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

How do the client-server and peer-to-peer models work, and how does the web fit in?

Understand the client-server and peer-to-peer models, web technologies including HTML, CSS and JavaScript, the role of web servers, and the use of APIs and thin versus thick clients.
A focused answer to AQA A-Level Computer Science 4.8.6, covering the client-server and peer-to-peer models, web technologies including HTML, CSS and JavaScript, the role of web servers, and thin versus thick clients.
8 min answer →

How is data physically transmitted between devices?

Understand serial and parallel transmission, synchronous and asynchronous transmission, bit rate, baud rate and bandwidth, and the trade-offs between these methods.
A focused answer to AQA A-Level Computer Science 4.8.1, covering serial and parallel transmission, synchronous and asynchronous transmission, the meaning of bit rate, baud rate and bandwidth, and the trade-offs between methods.
8 min answer →

How are networks kept secure and how does encryption protect data?

Understand network security threats, firewalls and proxy servers, the use of encryption, digital certificates and digital signatures, and the difference between symmetric and asymmetric encryption in transmission.
A focused answer to AQA A-Level Computer Science 4.8.5, covering network security threats, firewalls and proxy servers, encryption in transmission, digital certificates and digital signatures, and symmetric versus asymmetric encryption.
9 min answer →

What are the main network types, topologies and the role of network hardware?

Understand LANs and WANs, star and bus topologies, wired and wireless networks, the role of switches, routers and the Wi-Fi standards including CSMA/CA and SSID.
A focused answer to AQA A-Level Computer Science 4.8.2 and 4.8.3, covering LANs and WANs, star and bus topologies, wired versus wireless networks, network hardware, and wireless networking with CSMA/CA and the SSID.
9 min answer →

How does the internet work, and what is the TCP/IP protocol stack?

Understand the structure of the internet, packet switching, the TCP/IP four-layer model, IP addressing, DNS, routers and gateways, and how data is routed across networks.
A focused answer to AQA A-Level Computer Science 4.8.4, covering the structure of the internet, packet switching, the TCP/IP four-layer model, IP addressing, DNS, routers and gateways, and how data is routed across networks.
9 min answer →