Each device which is connected to the web has a special identifier named IP (Internet Protocol) address. This includes PCs, web servers, smartphones, switches, etc. The pool of addresses, that was introduced initially, is already distributed, so the so-called IPv4 IP addresses are slowly getting replaced with IPv6 addresses. Every domain name that 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 with a dot, while with the IPv6 system it's called AAAA and it comprises of eight groups of hexadecimal numbers i.e. this sort 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 greater number of IPs in comparison with the IPv4 format.