Every single device that is connected to the world wide web has a distinctive identifier named IP (Internet Protocol) address. This includes PCs, web servers, smart phones, switches, etcetera. The pool of addresses, which was introduced initially, has already been distributed, hence the so-called IPv4 IP addresses are slowly getting replaced with IPv6 addresses. Every domain which opens an internet site has an IP record, which is the address of the server where it is hosted. When using the IPv4 system, the record is called A and it is made up of 4 groups of numbers from 1 to 255 separated with a dot, while with the IPv6 system it's 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. An example of an AAAA record is 2010:0c48:43d3:2142:1012:8c3a:2475:2435 and this format works with a substantially larger amount of IPs when compared with the IPv4 format.