Each device that is connected to the web has a unique identifier referred to as IP (Internet Protocol) address. This includes computers, web servers, smart phones, switches, etcetera. The pool of IP addresses, that was introduced initially, has been distributed, therefore the so-called IPv4 IP addresses are gradually getting replaced with IPv6 addresses. Every domain name which opens an internet site has an IP record, which is the address of the server where it is hosted. With the IPv4 system, the record is called A and it comprises of four sets of numbers from 1 to 255 divided using a dot, while with the IPv6 system it's called AAAA and it comprises of eight sets of hexadecimal numbers i.e. this sort of records use numbers 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 substantially larger amount of IPs than the IPv4 format.