Each device which is connected to the web has a special identifier called IP (Internet Protocol) address. This includes personal computers, web servers, smart phones, switches, etcetera. The pool of addresses, that was introduced originally, has already been distributed, hence the so-called IPv4 IP addresses are gradually 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 sets of numbers from 1 to 255 divided using a dot, while in the IPv6 system it is called AAAA and it comprises of 8 groups of hexadecimal numbers i.e. this type of records use digits from 0 to 9 and letters from A to F. An example of an AAAA record is 2010:0c48:43d3:2142:1012:8c3a:2475:2435 and this format can handle a significantly larger number of IPs when compared with the IPv4 format.