Every single device which is connected to the web has a special identifier referred to as IP (Internet Protocol) address. This includes PCs, web servers, smartphones, switches, etc. The pool of addresses, that was introduced initially, has been distributed, so the so-called IPv4 IP addresses are gradually being replaced with IPv6 addresses. Every domain which opens an internet site has an IP record, which is the address of the server where it's hosted. With the IPv4 system, the record is called A and it consists of 4 groups of numbers from 1 to 255 separated by a dot, while in the IPv6 system it's called AAAA and it consists of 8 groups of hexadecimal numbers i.e. this kind of records use digits from 0 to 9 and letters from A to F. An illustration of an AAAA record is 2010:0c48:43d3:2142:1012:8c3a:2475:2435 and this format supports a considerably larger amount of IPs when compared with the IPv4 format.