Every single device that's connected to the world wide web has a special identifier known as IP (Internet Protocol) address. This includes computer systems, web servers, smart phones, switches, etcetera. The pool of IPs, that was introduced originally, has been distributed, therefore the so-called IPv4 IP addresses are slowly being replaced with IPv6 addresses. Every domain that opens a site comes with 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 4 sets of numbers from 1 to 255 divided using a dot, while with the IPv6 system it's called AAAA and it is made up of 8 groups of hexadecimal numbers i.e. this kind of records use digits 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 works with a substantially larger number of IPs compared with the IPv4 format.