Each device that's connected to the web has a unique identifier referred to as IP (Internet Protocol) address. This includes personal computers, web servers, smartphones, switches, and so on. The pool of IP addresses, that was introduced initially, is already distributed, therefore the so-called IPv4 IP addresses are slowly getting replaced with IPv6 addresses. Every domain name that opens a website comes with 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 comprises of four groups of numbers from 1 to 255 separated with a dot, while in the IPv6 system it's called AAAA and it consists of 8 groups of hexadecimal numbers i.e. this sort 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 significantly greater number of IPs compared with the IPv4 format.