Each device that is connected to the Internet has a special identifier referred to as IP (Internet Protocol) address. This includes computers, web servers, smart phones, switches, etcetera. The pool of addresses, which was introduced at first, is already distributed, therefore the so-called IPv4 IP addresses are steadily being replaced with IPv6 addresses. Every domain that opens a site comes with an IP record, that is the address of the server where it is hosted. With the IPv4 system, the record is called A and it consists of four groups of numbers from 1 to 255 separated with a dot, while within 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 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 is designed for a considerably bigger number of IPs when compared with the IPv4 format.