Every single device that's connected to the web has a special identifier referred to as IP (Internet Protocol) address. This includes computer systems, web servers, smartphones, switches, etc. The pool of IPs, which was introduced originally, has been distributed, so the so-called IPv4 IP addresses are progressively being 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. Using the IPv4 system, the record is called A and it is made up of four sets of numbers from 1 to 255 separated by a dot, while with 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 is designed for a substantially larger amount of IPs compared with the IPv4 format.