IP Addresses and DNS
An IP address is a unique number identifying a device on a network, and DNS turns website names into IP addresses.
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An IP address is a unique number identifying a device on a network, and DNS turns website names into IP addresses.
- IPv4 uses four numbers
- IPv6 has more addresses
- DNS works like a phone book
🧠 Quick quiz
Three questions. Score 2 or more to complete the topic.
What is IP Addresses and DNS?
Within Computer Science, which covers algorithms, programming, data, networks, hardware and safe, responsible use of technology, this topic explains IP Addresses and DNS. Computing topics explain how software, hardware and data work, with diagrams and models that show each step in order.
Check that you can explain IP Addresses and DNS in your own words and give one example from everyday life. If you can do that, you have understood the core idea.
Understanding IP Addresses and DNS helps you design, test and explain programs, websites and systems, from small projects to exam questions.
IP Addresses and DNS in detail
An IP address is a unique number identifying a device on a network, like a postal address. IPv4 addresses have four numbers from 0 to 255 (such as 192.168.1.1), and IPv6 uses longer hexadecimal addresses because IPv4 addresses are running out. Addresses can be static or dynamic, and a router often has a public address while devices use private ones.
The Domain Name System (DNS) works like a phone book, translating human-friendly names such as example.com into IP addresses, using a hierarchy of DNS servers. Without it, we would need to remember numbers. A MAC address is a hardware identifier built into the network card.
How the interactive helps you understand IP Addresses and DNS
Watch the network in the interactive. Use any sliders or buttons it offers to change the values and see how the network responds.
Before you change anything, predict the result. Then change one value at a time and check whether your prediction was right. This is a quick way to build a correct mental model of IP Addresses and DNS.
Real-life uses and examples
- Trace through a process that uses IP Addresses and DNS to check what it does step by step.
- Recognise IP Addresses and DNS in an app or device you use every day.
- Apply IP Addresses and DNS when you design a small program, website or spreadsheet.
Common mistakes to avoid
- Testing only the normal case and forgetting the edge cases.
- Using the term without being able to say what the computer actually does.
- Learning the definition without testing it. Use the quiz and the interactive to check that you can apply the idea.
Frequently asked questions about IP Addresses and DNS
What is IP Addresses and DNS?
An IP address is a unique number identifying a device on a network, and DNS turns website names into IP addresses.
What are the most important points about IP Addresses and DNS?
The main points are: IPv4 uses four numbers; IPv6 has more addresses; DNS works like a phone book.
Why is IP Addresses and DNS useful?
Understanding IP Addresses and DNS helps you design, test and explain programs, websites and systems, from small projects to exam questions.
How can I practise IP Addresses and DNS?
Open the interactive at the top of this page and change the controls one at a time. Predict the result before each change, then take the three-question quiz. A score of two or more marks the topic as complete on this device.
Which topics are related to IP Addresses and DNS?
Related topics in Computer Science include Cloud Computing, Encryption, Digital Footprint.