Every single device that's connected to the world wide web has a special identifier known as IP (Internet Protocol) address. This includes computers, web servers, smart phones, switches, etc. The pool of IP addresses, which was introduced initially, has already been distributed, hence the so-called IPv4 IP addresses are steadily getting replaced with IPv6 addresses. Every domain name which opens a site comes with an IP record, that 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 divided using a dot, while with the IPv6 system it is 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 example of an AAAA record is 2010:0c48:43d3:2142:1012:8c3a:2475:2435 and this format is designed for a significantly larger number of IPs than the IPv4 format.