Every device that is connected to the world wide web has a special identifier called IP (Internet Protocol) address. This includes PCs, web servers, smartphones, switches, and so on. The pool of IPs, that was introduced initially, is already distributed, therefore the so-called IPv4 IP addresses are steadily being replaced with IPv6 addresses. Every domain name which opens a website comes with an IP record, which is the address of the server where it is hosted. Using the IPv4 system, the record is called A and it comprises of four sets of numbers from 1 to 255 split up using a dot, while with the IPv6 system it's called AAAA and it is made up of eight groups of hexadecimal numbers i.e. this kind of records use digits from 0 to 9 and letters from A to F. An illustration of an AAAA record is 2010:0c48:43d3:2142:1012:8c3a:2475:2435 and this format is designed for a considerably larger number of IPs than the IPv4 format.