Every single device which is connected to the world wide web has a unique identifier named IP (Internet Protocol) address. This includes PCs, web servers, smartphones, switches, etcetera. The pool of IP addresses, that was introduced at first, has been distributed, therefore the so-called IPv4 IP addresses are progressively getting replaced with IPv6 addresses. Every domain name which opens a site 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 comprised of four sets of numbers from 1 to 255 divided by a dot, while with the IPv6 system it's called AAAA and it consists of 8 sets of hexadecimal numbers i.e. this sort of records use numbers from 0 to 9 and letters from A to F. A good example of an AAAA record is 2010:0c48:43d3:2142:1012:8c3a:2475:2435 and this format can handle a substantially bigger amount of IPs than the IPv4 format.