What is an IP Address? Understand your digital address on the internet

When you use the internet, you leave traces everywhere – but did you know that your computer or mobile always has a kind of 'digital address'? This address is called an IP address, and it is necessary for you to surf the web, send emails, or stream videos. But what does IP address actually mean, and why is it so important?

What does IP stand for?

IP stands for Internet Protocol. It is a set of rules that determines how data is sent from one device to another over the internet. An IP address is a unique identification number that each device is assigned so it can communicate with other devices.

What does an IP address look like?

There are two main types of IP addresses:

• IPv4: The classic form, which consists of four numbers separated by periods, e.g. 192.168.1.1. Each number can be between 0 and 255.
• IPv6: A newer version that uses eight groups of letters and numbers separated by colons, e.g. 2001:0db8:85a3:0000:0000:8a2e:0370:7334. IPv6 was created because we are running out of IPv4 addresses.

What is an IP address used for?

An IP address works like a home address, but on the internet. When you visit a website, your computer sends a request to the web server's IP address. The web server sends the response back to your IP address so you can see the page. Without IP addresses, the internet wouldn't know where data should be sent – or where the response should go back to.

Example: How it works

1. You enter www.kgm.dk in your browser.
2. Your computer asks for the IP address of www.kgm.dk (this happens via DNS, which is the internet's "phone book").
3. The request is sent to the web server behind the correct IP address.
4. The web server sends the content back to your IP address.

Public and private IP addresses

There are two types of IP addresses:

• Public IP address: The address your home network uses externally on the internet. This is the address that websites see when you visit them.
• Private IP address: Addresses used internally in your home or office, e.g. for your computers, mobiles, or printers. These addresses are not visible on the internet.

Your router assigns private IP addresses to your devices and ensures that traffic is sent out to the internet via the public IP address.

Static vs. dynamic IP address

An IP address can either be static (fixed) or dynamic (changing):

• Static IP: Never changes. Often used by servers or businesses that need to be easy to find on the internet.
• Dynamic IP: Changes automatically, typically every time you restart your router or at regular intervals. Most private users get dynamic IP addresses.

Who assigns IP addresses?

It is your internet provider (ISP) that gives you a public IP address. Private addresses are assigned by your router via a technology called DHCP. Globally, IP addresses are managed by organizations such as IANA and RIPE NCC.

IP addresses and privacy

An IP address does not directly say who you are, but it can often be used to find out which provider and which geographic area you are in. Therefore, IP addresses are used for everything from troubleshooting and network monitoring to targeted advertising and, in some cases, prosecution.

How to protect your IP address

• Use a VPN (Virtual Private Network) to hide your real IP address.
• Make sure your network is secure so others cannot misuse your IP address.

Conclusion

An IP address is the very foundation for communication on the internet. Without IP addresses, it would not be possible to send and receive data between computers and servers. Understanding IP addresses not only helps you understand how the internet is structured, but also makes you more aware of your digital footprint and online security.