Every device that is connected to the web has a unique identifier referred to as IP (Internet Protocol) address. This includes PCs, web servers, smartphones, switches, etcetera. The pool of addresses, that was introduced at first, has already been distributed, therefore the so-called IPv4 IP addresses are slowly being replaced with IPv6 addresses. Every domain name that opens a website comes with an IP record, that is the address of the server where it's hosted. When using the IPv4 system, the record is called A and it is comprised of four groups of numbers from 1 to 255 separated by a dot, while within the IPv6 system it's called AAAA and it is comprised of 8 sets of hexadecimal numbers i.e. this sort of records use digits 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 is designed for a considerably greater amount of IPs in comparison with the IPv4 format.