Every single device that is connected to the web has a unique identifier referred to as IP (Internet Protocol) address. This includes personal computers, web servers, smart phones, switches, etcetera. The pool of IP addresses, which was introduced initially, is already distributed, hence the so-called IPv4 IP addresses are gradually getting replaced with IPv6 addresses. Every domain name that opens a website has an IP record, that is the address of the server where it's hosted. When using the IPv4 system, the record is called A and it consists of 4 groups of numbers from 1 to 255 separated by a dot, while within the IPv6 system it's called AAAA and it comprises of eight groups of hexadecimal numbers i.e. this kind 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 considerably bigger number of IPs when compared with the IPv4 format.