Every single device that's connected to the Internet has a special identifier called IP (Internet Protocol) address. This includes computer systems, web servers, smart phones, switches, and so on. The pool of IP addresses, that was introduced initially, has already been distributed, hence the so-called IPv4 IP addresses are progressively getting replaced with IPv6 addresses. Every domain name which opens a website has 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 is comprised of four sets of numbers from 1 to 255 separated with a dot, while in the IPv6 system it's called AAAA and it is made up of eight sets of hexadecimal numbers i.e. this type 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 significantly larger amount of IPs in comparison with the IPv4 format.