Each device that is connected to the web has a distinctive identifier referred to as IP (Internet Protocol) address. This includes PCs, web servers, smartphones, switches, and so on. The pool of IPs, that was introduced originally, has already been distributed, hence the so-called IPv4 IP addresses are steadily being replaced with IPv6 addresses. Every domain that opens a site comes with 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 consists of 4 sets of numbers from 1 to 255 separated using a dot, while in the IPv6 system it's called AAAA and it comprises of 8 sets of hexadecimal numbers i.e. this kind of records use numbers 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 than the IPv4 format.