IGCSE Computer Science: The Internet and Its Uses — Practice Questions (Cambridge 0478)

These are original questions written for Marlbridge, for revision and practice on this content. They are not reproduced past-paper questions, and they do not replicate the exam’s exact structure, question count or mark tariffs — Cambridge International holds copyright in its own papers. Use these alongside the official past papers available free from your board.

Related: The internet and its uses study guide and revision notes

These questions cover all three sub-topics of Topic 5 in the Cambridge IGCSE Computer Science 0478 syllabus (2026–2028): the internet and the world wide web (5.1), digital currency (5.2) and cyber security (5.3). Topic 5 is assessed on Paper 1.

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Section A

1. A student says, “The internet and the world wide web are the same thing.” Explain why the student is wrong. [2]

2. State the purpose of HTTP, and describe how HTTPS is different. [3]

3. A web browser has an address bar. Identify two other functions of a web browser, other than providing an address bar. [2]

4. State what is meant by a digital currency. [1]

Section B

5. The statements A to F describe how a web page is located, retrieved and displayed, but they are in the wrong order. Write the letters in the correct order. [4]

• A — The web server sends the HTML for the page back to the browser.
• B — The user enters the URL in the browser.
• C — The browser renders the HTML and displays the page.
• D — The DNS returns the IP address of the web server.
• E — The browser sends the domain name to a DNS.
• F — The browser uses the IP address to request the page from the web server.

6. A travel website uses cookies.

(a) State what is meant by a cookie. [1] (b) The website remembers a user’s preferred language each time they return over several months. State which type of cookie is used and explain why. [2] (c) Give two other uses of cookies. [2]

7. A small online games company is hit by a distributed denial of service (DDoS) attack.

(a) Describe the process of a DDoS attack. [3] (b) State the aim of the attack. [1] (c) Identify one solution that could help reduce the effect of the attack and explain how it helps. [2]

8. Describe the difference between each pair of malware. [4]

(a) A virus and a worm. (b) Spyware and ransomware.

9. An employee receives a phone call from someone claiming to be from the company’s IT department. The caller asks for the employee’s password to “fix a problem with their account”.

(a) Identify the cyber security threat. [1] (b) Explain why access levels would limit the damage if the employee gave away their password. [2]

10. A school’s network administrator wants to protect pupils’ data. Explain how each of the following helps keep data safe: [6]

(a) automating software updates (b) a proxy server (c) biometric authentication

11. Explain how blockchain is used to track digital currency transactions. [3]

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Answers

1. The internet is the infrastructure: the worldwide network of connected computers and networks [1]. The world wide web is the collection of websites and web pages that are accessed using the internet [1].

2. HTTP is the set of rules (protocol) used to transfer web pages between a web server and a browser [1]. HTTPS uses the same rules but is secure [1]: the data is encrypted (using SSL), so if it is intercepted it cannot be understood [1].

3. Any two from: storing bookmarks/favourites; recording user history; allowing multiple tabs; storing cookies; providing navigation tools (such as back and forward buttons) [1 each, max 2].

4. A currency that only exists electronically [1].

5. B, E, D, F, A, C. One mark each for: B first [1]; E immediately followed by D [1]; F immediately followed by A [1]; C last [1].

Tip: the DNS only supplies the IP address. Pupils often put “the DNS sends the page”, which is never credited.

6. (a) A small text file stored on the user’s device by the web browser for a website [1]. (b) A persistent cookie [1], because it stays on the device after the browser is closed until it expires or is deleted, so the preference is still there on the next visit [1]. (c) Any two from: saving personal details; holding items in an online shopping cart; storing login details; tracking user preferences (other than language, already given) [1 each, max 2].

7. (a) Any three from:

• the attacker infects many computers with malware, creating a botnet [1]
• the attacker instructs these computers to send requests to the company’s server at the same time [1]
• the server receives far more requests than it can handle [1]
• so it slows down or crashes / genuine users’ requests cannot be processed [1]

(b) To make the website or server unavailable to genuine users [1]. (c) A firewall [1] can monitor incoming traffic and block requests that do not meet its rules, such as many requests from the same IP addresses [1]. Or: a proxy server [1] can filter traffic before it reaches the web server, absorbing some of the requests [1].

8. (a) A virus attaches itself to a file and replicates when the infected file is run [1]; a worm replicates itself and spreads across a network without needing a user to run a file [1]. (b) Spyware records the user’s actions, such as key presses, and sends the data to a third party [1]; ransomware encrypts the user’s files and demands payment for the decryption key [1].

9. (a) Social engineering [1]. (b) Access levels mean each user can only open the data and areas of the system their role needs [1], so an attacker using the employee’s password could only reach that employee’s data, not the whole system [1].

10. Two marks each — one for what it does, one for how this protects data:

(a) Updates are downloaded and installed automatically as soon as they are released [1], so security weaknesses that attackers could exploit are fixed quickly without relying on the administrator remembering [1]. (b) A proxy server sits between the school network and the internet [1]; it hides the internal IP addresses and can filter traffic, blocking access to unsafe websites [1]. (c) Biometric authentication uses a unique physical feature such as a fingerprint or face [1], which is hard to copy or guess, so only the genuine user can log in [1].

11. Any three from:

• blockchain is a digital ledger: a time-stamped series of records [1]
• each transaction is stored as a block that cannot be altered [1]
• each block contains a hash of the previous block, linking them in a chain [1]
• copies of the chain are held on many computers, so any change to one copy would not match the others and is rejected [1]

Where marks are usually lost

• Question 2: saying HTTPS is “more secure” without saying how — the data is encrypted.
• Q7(a): describing one computer sending many requests. A DDoS attack needs many computers.
• Question 8: describing what both malware types have in common instead of the difference between them.
• Question 10: naming what the solution is but not how it keeps data safe — each part has a mark for both.

Frequently asked questions

How many cyber security threats does 0478 list? Eight headings: brute-force attack, data interception, DDoS, hacking, malware (six named types), pharming, phishing and social engineering. You need both the process and the aim of each.

Is SSL the same as HTTPS? No. SSL is the security protocol that encrypts the data; HTTPS is HTTP running over that secure, encrypted connection.

Do I need to know how a digital currency is mined? No. The 0478 syllabus limits digital currency to the concept, how it is used and blockchain in its basic form.