Each device that's connected to the world wide web has a special identifier known as IP (Internet Protocol) address. This includes computer systems, web servers, smartphones, switches, and so on. The pool of IPs, which was introduced at first, has already been distributed, hence the so-called IPv4 IP addresses are steadily being replaced with IPv6 addresses. Every domain which opens a website has an IP record, that is the address of the server where it's hosted. With the IPv4 system, the record is called A and it is made up of 4 groups of numbers from 1 to 255 split up by a dot, while with the IPv6 system it's called AAAA and it consists of 8 sets of hexadecimal numbers i.e. this type 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 substantially greater number of IPs in comparison with the IPv4 format.