Each device which is connected to the Internet has a special identifier known as IP (Internet Protocol) address. This includes computers, web servers, smart phones, switches, and so on. The pool of IP addresses, which was introduced initially, has been distributed, so the so-called IPv4 IP addresses are steadily being replaced with IPv6 addresses. Every domain name which opens a site has an IP record, which is the address of the server where it's hosted. Using the IPv4 system, the record is called A and it consists of four sets of numbers from 1 to 255 separated using a dot, while in the IPv6 system it is called AAAA and it is made up of eight groups of hexadecimal numbers i.e. this kind 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 supports a considerably bigger amount of IPs when compared with the IPv4 format.