Each device which is connected to the web has a special identifier known as IP (Internet Protocol) address. This includes PCs, web servers, smartphones, switches, etc. The pool of IPs, that was introduced at first, has been distributed, therefore the so-called IPv4 IP addresses are progressively getting replaced with IPv6 addresses. Every domain name which opens an internet site has 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 consists of four sets of numbers from 1 to 255 divided with a dot, while in the IPv6 system it's called AAAA and it consists of 8 groups of hexadecimal numbers i.e. this type 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 works with a considerably larger amount of IPs than the IPv4 format.