Every device that's connected to the world wide web has a unique identifier referred to as IP (Internet Protocol) address. This includes computer systems, web servers, smartphones, switches, etcetera. The pool of IPs, which was introduced originally, has been distributed, so the so-called IPv4 IP addresses are gradually being replaced with IPv6 addresses. Every domain which opens a site 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 is comprised of four sets of numbers from 1 to 255 separated by a dot, while in the IPv6 system it's called AAAA and it consists of 8 groups of hexadecimal numbers i.e. this sort of records use digits 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 is designed for a significantly bigger number of IPs compared with the IPv4 format.