Every single device that is connected to the web has a distinctive identifier named IP (Internet Protocol) address. This includes computer systems, web servers, smart phones, switches, etc. The pool of addresses, which was introduced at first, is already distributed, so the so-called IPv4 IP addresses are progressively being replaced with IPv6 addresses. Every domain that opens an internet site has an IP record, that is the address of the server where it's hosted. With the IPv4 system, the record is called A and it is comprised of 4 sets of numbers from 1 to 255 divided using a dot, while within 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 illustration of an AAAA record is 2010:0c48:43d3:2142:1012:8c3a:2475:2435 and this format can handle a substantially bigger number of IPs compared with the IPv4 format.