Each device which is connected to the world wide web has a unique identifier named IP (Internet Protocol) address. This includes computer systems, web servers, smart phones, switches, and so on. The pool of addresses, that was introduced at first, has been distributed, so the so-called IPv4 IP addresses are steadily being replaced with IPv6 addresses. Every domain that opens a site has an IP record, that is the address of the server where it is hosted. When 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 with the IPv6 system it is called AAAA and it consists of eight sets of hexadecimal numbers i.e. this kind 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.