Every device which is connected to the web has a special identifier named IP (Internet Protocol) address. This includes computer systems, web servers, smart phones, switches, and so on. The pool of addresses, which was introduced initially, is already distributed, so the so-called IPv4 IP addresses are slowly being replaced with IPv6 addresses. Every domain name which opens an internet site 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 consists of 4 sets of numbers from 1 to 255 separated with a dot, while with the IPv6 system it's called AAAA and it consists of 8 sets of hexadecimal numbers i.e. this kind 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 works with a substantially bigger amount of IPs in comparison with the IPv4 format.