Each device which is connected to the Internet has a unique identifier called IP (Internet Protocol) address. This includes computers, web servers, smartphones, switches, etcetera. The pool of IPs, that was introduced originally, has already been distributed, hence the so-called IPv4 IP addresses are gradually being replaced with IPv6 addresses. Every domain which opens a website comes with an IP record, that is the address of the server where it's hosted. Using the IPv4 system, the record is called A and it comprises of 4 sets of numbers from 1 to 255 separated using a dot, while in the IPv6 system it is called AAAA and it is made up of eight 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 significantly larger number of IPs than the IPv4 format.