If you have even remotely engaged with the internet at any point in your lives, which I hope everyone reading this has, you have implicitly encountered what is known as your IP address without knowing. Understanding them means you don’t have to go to r/hacking to ask if a leak of your IP will mean someone will come to your house and shoot you. Spoiler, they could (technically). 
 
It is important to clarify the use of the IP address. IP, or Internet Protocol works by selecting paths for data and traffic (routing) and allows internetworking between computers which facilitates the internet itself. You can probably then guess that the ‘address’ aspect suggests that the IP address serves as a marker for the host or network interface. The IP also provides the location of the network interface, therefore allowing the network to establish a path to the host. Therefore, it is crucial in allowing your computer to access the internet. 
 
This address is not necessarily fixed, raising the distinction between so called dynamic and static IP addresses. Most devices use dynamic IP addresses, which networks assign to a device when they connect and so change over time. This is to reflect that dynamic IP addresses come with ‘dynamic’ devices, like phones and laptops, ones which move and so must have variable addresses to ensure they can connect with the internet. Static IP’s are the opposite as their address never changes. Static Addresses tend to feature in devices that need to be always accessible. For example, if a computer is configured as a server, like a web or FTP server, users must be able to access the computer to perform functions like file downloading. Another common example is a printer which must be accessible by everyone in a school, office, or household and when every individual computer is set up to connect to that printer, those connections remain indefinitely. 
 
Another key difference between static and dynamic IP addresses is how they are set up. Statics are set up manually whereas dynamic addresses are assigned automatically by something called the DHCP (Dynamic Host Configuration Protocol). The DHCP can monitor the usage of this address and recall it after a period of inactivity. This difference makes the advantages and disadvantages of each quite distinct. 
 
As DHCP is not universal, static is the only option for certain devices. Their manual nature means that automatic IP address conflicts, where multiple devices share an IP (usually because one was put into hibernation and made inactive, a problem for IPv4 that I cover later), don’t occur, assuming no human error. Dynamic addresses tend to allow flexibility for a network admin when adding new devices to systems. Imagine if the IT Department had to manually assign each new iPad their own IP address that wouldn’t connect to the internet as soon as they left Eton. The Wi-Fi might be even less close to working. The seamless nature of IP reassignment when moving between networks simply makes Dynamic addresses more convenient. Notably though, neither type has a particular advantage in terms of security, because ultimately if your Wi-Fi security is broken, both are equally vulnerable. 
 
Now that I’ve covered some of the uses and types of IP addresses, I need to cover the versions of IP addresses and its history. IP addresses first popped up in the 70’s but the development of Internet Protocol version 4 (IPv4) in 1983 is the version from the Stone age that remains today. It contains 32 bits and so has about 4.3 billion possible addresses. Some of these are reserved for private networks for example, but despite the vast majority being open access, the addresses were quickly exhausted. Therefore in 2006, IPv6 was introduced with its 32 hexadecimals (equivalent to 128 bits) which means there is a truly gargantuan array of addresses that can be accessed. It means that addresses don’t have to be reused, which makes it less prone to error than IPv4.Other versions have been created, from versions 1-9, but they haven’t caught on as significantly. 
 
An example of how an IPv6 is laid out is shown below.
 

 
Where each group has 4 hexadecimal numbers and groups, which are indicated after every colon, which have just zeroes are omitted from the simplified version. In order to bring order to how IPv6’s are implemented, there is something called subnetting, but this is a topic that deserves its own article. 
 
Now the burning question that has caused sleepless nights for many is what can someone do if they possess your IP address?  
 
On the less hostile end of things, some advertisers have started using embedded tracking programs in online articles. These trackers can record your IP address and send you email advertisements that are more relevant to where you live or the interests you have. So if you start getting emails from vendors selling pregnant pigs, you probably shouldn’t take biology notes from that website. Companies can also use your location to restrict access to their services. Netflix might restrict you from seeing certain tv shows and movies if you live in one country or charge you a different rate depending on where you live. Therefore, you might use a VPN to disguise your location to prevent these problems. 
 
But letting your IP address be found by those who seek harm can be dangerous as well. They can track your location, and with your social media updates, could know when you aren’t at home and rob you. Hackers can also execute Denial of Service (DoS) or more intense distributed DoS. This blocks you from accessing network resources, like websites, online accounts, and email. This method floods your address with server requests, which overloads your system with traffic. They can also use your IP to phish your personal information by sending you emails that encourage you to input sensitive information. This information can then be sold and exposed in the public domain.   
 
On the extreme end, IP breaches can lead you to being framed from crimes like drug buying and viewing child pornography. This can be achieved by a hacker using your IP address to impersonate you online, routing their activity through your address. However, this is very effort intensive and requires a lot of skill. 
 
The solution to all these problems is to use a VPN (virtual private network) which changes your IP to a different IP address in some far-flung land so that it appears you are connecting to the internet from a different location, the location of the VPN server.  
 
Hopefully, I have provided you with some knowledge about an aspect of modern technology that is often thrown about without much care or consideration. IP’s have short but sweet history and although their vulnerability causes much strife, they are vital to having a functioning internet.