Every single device that's connected to the web has a specific identifier referred to as IP (Internet Protocol) address. This includes computer systems, web servers, smart phones, switches, etc. The pool of IP addresses, that was introduced at first, is already distributed, therefore the so-called IPv4 IP addresses are slowly being replaced with IPv6 addresses. Every domain name that opens an internet site has an IP record, which is the address of the server where it's hosted. Using the IPv4 system, the record is called A and it is made up of four groups of numbers from 1 to 255 separated by a dot, while within the IPv6 system it is 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. A good example of an AAAA record is 2010:0c48:43d3:2142:1012:8c3a:2475:2435 and this format supports a significantly larger number of IPs compared with the IPv4 format.