IP Address Definition: Like a phone number, an IP address is a unique number for an internet connection or for a server where a website is hosted. When you buy a domain name, you’ll need to point it at your web host’s IP address. There are different versions of an IP address such as v4 “196.160.5.188” or the latest version (v6) which has a greater number of unique addresses and comes in this format: “2009:0db6:80a3:0005:0000:6a3e:0970:7734”.