Every single device that's connected to the web has a special identifier called IP (Internet Protocol) address. This includes PCs, web servers, smart phones, switches, etc. The pool of addresses, which was introduced at first, has already been distributed, therefore the so-called IPv4 IP addresses are gradually getting replaced with IPv6 addresses. Every domain name that opens a website comes with an IP record, that is the address of the server where it is hosted. When using the IPv4 system, the record is called A and it consists of 4 groups of numbers from 1 to 255 split up using a dot, while within the IPv6 system it's called AAAA and it is made up of eight groups of hexadecimal numbers i.e. this sort of records use digits 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 is designed for a considerably greater number of IPs in comparison with the IPv4 format.