Every single device which is connected to the world wide web has a unique identifier known as IP (Internet Protocol) address. This includes computer systems, web servers, smartphones, switches, etc. The pool of addresses, that was introduced at first, has already been distributed, hence the so-called IPv4 IP addresses are gradually getting replaced with IPv6 addresses. Every domain which opens an internet site has an IP record, which is the address of the server where it's hosted. When using the IPv4 system, the record is called A and it is made up of 4 groups of numbers from 1 to 255 split up by a dot, while in the IPv6 system it is called AAAA and it comprises of eight groups of hexadecimal numbers i.e. this sort 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 works with a significantly bigger number of IPs than the IPv4 format.