Each device that is connected to the Internet has a specific identifier referred to as IP (Internet Protocol) address. This includes personal computers, web servers, smartphones, switches, etc. The pool of addresses, that was introduced initially, has already been distributed, therefore the so-called IPv4 IP addresses are slowly being replaced with IPv6 addresses. Every domain which opens a site has an IP record, that is the address of the server where it's hosted. Using the IPv4 system, the record is called A and it is made up of four sets of numbers from 1 to 255 separated using a dot, while with the IPv6 system it is called AAAA and it is comprised of 8 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 works with a substantially bigger number of IPs when compared with the IPv4 format.