Every single device that's connected to the world wide web has a distinctive identifier known as IP (Internet Protocol) address. This includes computers, web servers, smart phones, switches, etcetera. The pool of addresses, which was introduced initially, is already distributed, hence the so-called IPv4 IP addresses are gradually being replaced with IPv6 addresses. Every domain name that opens a site comes with an IP record, which is the address of the server where it is hosted. Using the IPv4 system, the record is called A and it is made up of 4 groups of numbers from 1 to 255 separated using a dot, while within the IPv6 system it's called AAAA and it is made up of eight sets of hexadecimal numbers i.e. this sort 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 works with a considerably larger amount of IPs than the IPv4 format.