Every device that is connected to the web has a unique identifier known as IP (Internet Protocol) address. This includes computers, web servers, smartphones, switches, etc. The pool of addresses, that was introduced originally, has already been distributed, hence the so-called IPv4 IP addresses are gradually getting replaced with IPv6 addresses. Every domain name which opens a site comes with 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 is comprised of 4 groups of numbers from 1 to 255 divided using a dot, while with the IPv6 system it's called AAAA and it is comprised of eight sets 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 can handle a considerably bigger number of IPs when compared with the IPv4 format.