Every device that is connected to the world wide web has a unique identifier named IP (Internet Protocol) address. This includes personal computers, web servers, smart phones, switches, and so on. The pool of addresses, which was introduced initially, is already distributed, therefore the so-called IPv4 IP addresses are slowly getting replaced with IPv6 addresses. Every domain which opens an internet site has 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 4 sets of numbers from 1 to 255 separated by a dot, while in the IPv6 system it's called AAAA and it is made up of eight groups 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 substantially bigger number of IPs in comparison with the IPv4 format.