Every device that's connected to the world wide web has a special identifier referred to as IP (Internet Protocol) address. This includes PCs, web servers, smart phones, switches, etcetera. The pool of IP addresses, that was introduced at first, is already distributed, hence the so-called IPv4 IP addresses are gradually getting replaced with IPv6 addresses. Every domain name which opens a site comes with an IP record, which is the address of the server where it is hosted. With the IPv4 system, the record is called A and it is made up of 4 sets of numbers from 1 to 255 divided with a dot, while with the IPv6 system it is called AAAA and it comprises of 8 sets of hexadecimal numbers i.e. this type of records use numbers from 0 to 9 and letters from A to F. A good example of an AAAA record is 2010:0c48:43d3:2142:1012:8c3a:2475:2435 and this format supports a significantly bigger number of IPs compared with the IPv4 format.