Every single device which is connected to the Internet has a special identifier referred to as IP (Internet Protocol) address. This includes computer systems, web servers, smart phones, switches, and so on. The pool of addresses, that was introduced initially, has already been distributed, hence the so-called IPv4 IP addresses are steadily being 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's hosted. When using the IPv4 system, the record is called A and it comprises of four sets of numbers from 1 to 255 separated with a dot, while with the IPv6 system it is 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. 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 in comparison with the IPv4 format.