Lesson 4.9.3.1

4.9.3.1 The Internet and how it works Quiz: AQA Computer Science, Unit 9

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

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Lesson 4.9.3.1, The Internet and how it works: 20 multiple choice questions for the AQA Computer Science (7517), Unit 9: Fundamentals of communication and networking, written with Revision Ninja.

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The 20 questions

  1. What is a packet in a network?

    • A list of domain names stored in the cache of a DNS server
    • A continuous stream of data sent down one dedicated circuit for a single session
    • A signal that changes the state of a router's flags to indicate a fault
    • A block of data with a header, which is sent independently across the network

  2. What is packet switching?

    • Each packet's power is switched on and off by the sender to save energy during the transmission of the message
    • Data is split into packets that can take different routes and are reassembled at the destination
    • Data is encrypted so that only the destination can read it on arrival, using a key that is shared in advance
    • A dedicated circuit is reserved for the whole duration of each communication, so no other traffic can use the link

  3. What is the role of a router?

    • It converts digital data into analogue signals for the telephone line
    • It encrypts all packets before they leave the local network for the Internet
    • It stores domain names and matches them to IP addresses for all users of the Internet
    • It forwards packets between networks, choosing a route towards each packet's destination

  4. What is a gateway?

    • A wireless adapter that connects a laptop to a WiFi network, allowing the laptop to join the local network
    • A program that converts a URL into a numeric IP address for the browser, so that the request can be sent
    • A server that stores web pages and serves them to browsers on request, which is used by every home network
    • A device, often a router, that connects one network to another, such as a local network to the Internet

  5. What are the main components of a packet?

    • A payload of addresses, with the data itself stored inside the router
    • A header with addressing and control information, and a payload carrying the data
    • A clock signal, a start bit and a stop bit for each byte in the packet
    • A header that holds only the data, and a footer that holds the destination address

  6. What is a uniform resource locator (URL)?

    • A numeric address that identifies a single router on the Internet
    • A program that compresses web pages before they are downloaded to a browser
    • A unique hardware address burned into a network adapter when it is manufactured
    • A text address that gives the location of a resource and the protocol used to access it

  7. What is a fully qualified domain name (FQDN)?

    • A code that identifies the country in which a web page was first published, used by search engines
    • A numeric address that identifies a device on a local network, such as 192.168.0.10 on a home router
    • A domain name that gives the complete path through the DNS hierarchy, for example www.example.com
    • A name given to a router by its manufacturer for identification when it is first installed on a network

  8. What is a domain name?

    • A list of the services that a particular web server provides to clients
    • A human-readable name, such as example.com, that maps onto one or more IP addresses
    • A numeric address of the form 192.168.1.1 assigned to each web server
    • A program used to transfer files between a client and a server

  9. What is the purpose of DNS?

    • To encrypt the content of web pages sent to browsers over the Internet, so that the data cannot be intercepted
    • To store copies of web pages on distributed servers for quicker access, so that popular pages load faster
    • To translate domain names into IP addresses, so that requests can be routed to the correct host
    • To assign each device a private address when it joins a local network, so that devices can talk to each other

  10. How are domain names organised?

    • In a hierarchy, read from right to left, with a top-level domain such as .com or .uk at the top
    • Alphabetically, so that all names starting with the same letter are kept together
    • Randomly, so that each name is assigned to a server by chance
    • By IP address, so that each domain name is simply a copy of an IP address

  11. What is the purpose of an Internet registry?

    • To encrypt the traffic between each client and server on the Internet, so that the contents are private
    • To allocate and record domain names and IP addresses so that each is unique across the Internet
    • To provide the physical cables that connect routers across the world, so that data can travel between countries
    • To store copies of all web pages so that users load them faster, by caching the most popular sites

  12. In the URL https://www.example.org/news/page1.html, which part is the domain name?

    • /news/page1.html
    • www.example.org
    • https
    • page1.html

  13. In the URL https://www.example.org/news/page1.html, which part identifies the protocol?

    • www.example.org
    • https
    • news
    • page1.html

  14. Why is DNS essential when a user types a web address into a browser?

    • Browsers need an IP address to send packets, so DNS must convert the name typed into one
    • DNS allocates a port number to the browser for each request that it makes
    • DNS stores the web page content, so the browser can render it without contacting the server
    • DNS encrypts the URL so that routers cannot see the name typed by the user

  15. Explain how routing is achieved across the Internet.

    • A central computer assigns a route to each packet before it leaves the sender, and the packet follows that route
    • Each router examines the destination address and forwards the packet towards it, using its routing information
    • Packets follow a fixed path that is recorded in the DNS for each domain name, so the route is always the same
    • Every router holds a copy of every web page, so it can answer the request itself without passing it on

  16. The URL http://www.example.com/a/b/c.html contains a path. How many path segments does it have?

    • 4
    • 3
    • 2
    • 1

  17. Which statement about IP addresses and domain names is correct?

    • IP addresses are human-readable words chosen by the owner of the server
    • Domain names are unique to each device, but IP addresses are shared among all devices
    • One domain name can map to several IP addresses, and one IP address can host several domain names
    • Each domain name maps to exactly one IP address for ever, with no exceptions

  18. A router receives a packet whose destination is not on any network it is directly connected to. What does it do?

    • It forwards the packet to the next router on a path towards the destination
    • It converts the packet into a URL and sends the URL to the destination
    • It discards the packet and asks the sender to resend it using a different URL
    • It stores the packet until the destination device is switched on

  19. Why can packets belonging to one message arrive in a different order from the order they were sent?

    • Each packet is sent to a different DNS server, which returns it in a random order to the sending device for assembly
    • Packets are deliberately sent in random order to improve the security of the message, so that eavesdroppers are confused
    • Routers reverse the order of packets to keep the network balanced across its links, so that no route is overloaded
    • Packets can take different routes with different delays, so they may arrive out of sequence and must be reassembled

  20. Which header field is most important to a router when it routes a packet across the Internet?

    • The destination IP address
    • The sender's name in plain text, so that the recipient can read it
    • The encryption key for the payload, which is stored in the footer
    • The length of the payload in bytes, and nothing else

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