Every single device that is connected to the Internet has a unique identifier named IP (Internet Protocol) address. This includes computer systems, web servers, smart phones, switches, etc. The pool of IP addresses, that was introduced originally, has already been distributed, hence the so-called IPv4 IP addresses are slowly being replaced with IPv6 addresses. Every domain name that opens a site has an IP record, that is the address of the server where it is hosted. When using the IPv4 system, the record is called A and it consists 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 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 can handle a significantly bigger amount of IPs compared with the IPv4 format.