Each device that is connected to the web has a special identifier called IP (Internet Protocol) address. This includes personal computers, web servers, smartphones, switches, and so on. The pool of IPs, which was introduced at first, has been distributed, so the so-called IPv4 IP addresses are steadily 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. With the IPv4 system, the record is called A and it consists of 4 groups of numbers from 1 to 255 split up by a dot, while within 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 numbers 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 can handle a considerably greater number of IPs in comparison with the IPv4 format.