Every device that's connected to the Internet has a distinctive identifier named IP (Internet Protocol) address. This includes personal computers, web servers, smart phones, switches, and so on. The pool of IP addresses, which was introduced at first, is already distributed, hence the so-called IPv4 IP addresses are slowly being replaced with IPv6 addresses. Every domain which opens a website comes with an IP record, that is the address of the server where it is hosted. With the IPv4 system, the record is called A and it is comprised of four sets of numbers from 1 to 255 divided with a dot, while with the IPv6 system it's called AAAA and it is comprised of 8 sets of hexadecimal numbers i.e. this sort of records use digits from 0 to 9 and letters from A to F. An example of an AAAA record is 2010:0c48:43d3:2142:1012:8c3a:2475:2435 and this format works with a significantly larger amount of IPs than the IPv4 format.