Every device that's connected to the Internet has a specific identifier referred to as IP (Internet Protocol) address. This includes computer systems, web servers, smart phones, switches, and so on. The pool of IPs, which was introduced initially, has already been distributed, hence the so-called IPv4 IP addresses are slowly being replaced with IPv6 addresses. Every domain name that opens an internet site comes with an IP record, that is the address of the server where it is hosted. Using the IPv4 system, the record is called A and it comprises of four groups of numbers from 1 to 255 split up by a dot, while in the IPv6 system it is called AAAA and it is comprised of eight groups of hexadecimal numbers i.e. this kind of records use numbers 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 supports a significantly greater number of IPs than the IPv4 format.