What is the Internet? (1 mark)
A global system of connected computer networks that lets devices share data
What is the difference between the Internet and the World Wide Web? (3–5 marks)
The internet is the physical network of cables, satellites, and routers.
The web is a service that runs on the internet, made up of websites.
Web pages are accessed using browsers like Chrome or Safari.
The internet also includes other services like email, messaging, and streaming.
The internet uses data packets and protocols to transfer information
What is an IP address used for? (1 mark)
To identify a device on the internet and guide data to the correct destination
Why do we need the Domain Name System (DNS)? (1 mark)
To convert website names into IP addresses so devices can find the right server
What are data packets and why are they used? (3–5 marks)
Data packets are small pieces of a larger message
Each packet includes addresses, order number, and protocol.
They allow faster and more reliable data transmission.
Packets can take different routes and be reassembled at the end.
Only lost packets need to be resent, not the whole file
Name two services that are part of the Internet but not part of the Web. (2 marks)
Streaming
Give two protocols used for communication and explain what they do. (3–5 marks)
TCP checks if all packets arrive and reassembles them in order
HTTP is used to load and display web pages
IP ensures each packet is sent to the correct device
What is bandwidth and how is it measured? (1 mark)
It is the amount of data that can travel through a network per second, measured in Mbps.
What does Mbps stand for? (1 mark)
Megabits per secondComputer Science - 2. C….
Why are fibre optic cables better than copper cables? (3–5 marks)
Fibre optics send data as light, making them faster
They keep speed over long distances.
They are less affected by interference.
Copper cables use electricity, which is slower.
Copper cables lose speed over long distances
What is buffering and what causes it? (1 mark)
Buffering happens when your device can’t load data fast enough, often due to slow internet
What is the difference between download speed and upload speed? (1 mark)
Download speed is how fast you receive data; upload speed is how fast you send data
Name two things that can weaken a Wi-Fi signal. (2 marks)
Walls
Microwaves
How does internet speed affect tasks like streaming or gaming? (3–5 marks)
Slow speed causes videos to buffer or pause.
Fast speed allows smooth gameplay and quick loading.
High speed supports multiple devices using the internet at once.
Low speed increases lag in online games.
Tasks like video calls may freeze if bandwidth is low
What is a network topology? (1 mark)
It is the physical or logical layout of a networkComputer Science - 3. N….
Describe how data moves in a star topology. (1 mark)
Data travels through a central hub or switch which directs it to the right device
Give one advantage and one disadvantage of a bus topology. (2 marks)
Advantage: It is cheaper and uses less cable.
Disadvantage: A single cable failure can crash the entire network
What happens if the backbone cable in a bus network is damaged? (1 mark)
The entire network fails
Describe how a ring topology moves data and one risk it creates. (3–5 marks)
Devices are connected in a loop.
Data moves in one direction from one device to the next.
Each device passes the data to the next.
If one device or cable fails, the whole network can go down.
A dual ring may be needed to prevent full failure
What is a hybrid topology? (1 mark)
A network that combines two or more types of topologies
Why does the choice of topology matter in network design? (3–5 marks)
It affects the cost of building the network.
It determines how easy the network is to expand.
It influences how reliable the network is.
It changes how fast data travels.
A poor topology choice can limit future performance
What is a client-server network? (1 mark)
A network where a central server provides services and resources to client devices
What is a peer-to-peer network? (1 mark)
A network where all devices share resources directly without a central server
Give one advantage and one disadvantage of a client-server network. (2 marks)
Advantage: Easy to manage security and updates.
Disadvantage: If the server goes offline, the whole network may stop working
Give one advantage and one disadvantage of a peer-to-peer network. (2 marks)
Advantage: Cheap and simple to set up.
Disadvantage: Harder to manage security and file organisation
Why are client-server networks often used in schools? (3–5 marks)
They allow users to log in from any device.
Files are stored in one central location.
Teachers can control access to shared resources.
Updates and passwords are easier to manage.
It supports many users with consistent access
What is cloud computing and how does it relate to the client-server model? (3–5 marks)
Cloud computing stores files on remote internet servers.
Users (clients) access data through the internet.
The cloud provider (server) manages updates and backups.
Files are accessible from any device with internet.
This model uses the client-server structure
Name two examples of services that use the client-server model. (2 marks)
Gmail
Google Drive
What is encryption and why is it important? (3–5 marks)
Encryption scrambles data into code so only the right person can read it
It protects sensitive information like passwords and messages.
It is crucial when using public or shared networks.
Without it, hackers can intercept and read data.
It is a core tool in cybersecurity for protecting privacy
What is the difference between plaintext and ciphertext? (1 mark)
Plaintext is readable data; ciphertext is the encrypted, unreadable version
What is a key used for in encryption? (1 mark)
A key is used to encrypt or decrypt data, making it readable again
How does the Caesar Cipher work and why is it insecure today? (3–5 marks)
It shifts each letter in the alphabet by a fixed number
It is a basic substitution cipher.
It is easy to break using trial and error or pattern spotting.
It has very few possible keys.
Modern encryption is far more complex and secure
What is the difference between symmetric and asymmetric encryption? (3–5 marks)
Symmetric encryption uses the same key to lock and unlock data
Asymmetric encryption uses a public key to lock and a private key to unlock.
Asymmetric is more secure for internet use.
Symmetric is faster and simpler but less secure for sharing.
Both are used in different real-world systems
What is a brute-force attack? (1 mark)
It is a method of guessing every possible key until the right one is found
Give one example of a real-world app that uses encryption and explain how it protects your data. (3–5 marks)
WhatsApp uses end-to-end encryption
Only the sender and receiver can read the messages.
The company itself cannot see the contents.
This protects messages from hackers or spies.
It ensures private communication between users.
What is a data packet and what does it contain? (3–5 marks)
A data packet is a small chunk of a larger message
It includes the sender’s IP address.
It includes the receiver’s IP address.
It has a packet number for ordering.
It includes the protocol used to send it
Why is data split into packets when sent online? (1 mark)
It’s easier, faster, and safer to send small packets than one large file
What is packet switching and how does it work? (3–5 marks)
Packet switching lets each packet travel by the fastest route
Packets can arrive out of order and still be reassembled.
The system avoids delays by rerouting around busy or broken parts.
It keeps the internet reliable and fast.
Each packet carries instructions for reordering at the end.
What is the role of TCP in sending messages? (1 mark)
TCP checks that all packets have arrived and reassembles them correctly
How do packet numbers and IP addresses help reconstruct data? (3–5 marks)
IP addresses show where the data came from and where it’s going
Packet numbers indicate the correct order.
Even if packets arrive at different times, they can be reordered.
TCP uses the numbers to check what’s missing.
This ensures the full message is correct.
Name two internet protocols and describe what they are used for. (2 marks)
HTTP: Loads websites.
FTP: Transfers large files like games or videos
Why must all devices follow the same communication protocols? (3–5 marks)
Protocols are like shared rules for communication
Without them, devices would not understand each other.
They ensure data is sent, received, and read correctly.
Different protocols serve different purposes (e.g., email vs websites).
Following the same protocol avoids confusion or errors.