Every device that's connected to the world wide web has a special identifier called IP (Internet Protocol) address. This includes computer systems, web servers, smart phones, switches, etcetera. The pool of addresses, which was introduced initially, is already distributed, therefore the so-called IPv4 IP addresses are steadily getting replaced with IPv6 addresses. Every domain name which opens an internet site comes with an IP record, which is the address of the server where it's hosted. With the IPv4 system, the record is called A and it comprises of 4 sets of numbers from 1 to 255 separated by a dot, while within the IPv6 system it's called AAAA and it consists of eight groups of hexadecimal numbers i.e. this type 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 works with a significantly larger number of IPs than the IPv4 format.