web development terminology - ip address
You may have heard the use of the term "ip address" before, if you haven't you most likely will hear about it in the future if you have or intend to have a web presence.
IP Address - Internet Protocol Address
Networking equipment needs to have an address just as a location or home needs an address in order for someone to find it. The ip address is used on internet routers to know how to route traffic between them. Large ranges of IP addresses are assigned to different providers, and routing tables are maintained which are essentially lists of ranges of ips and which way to send the traffic.
This relates to websites because all web traffic is of course done on the internet and will need to be routed by ip address just like any other traffic would be. Website domains at a lower level inside computers resolve to an ip address which will route on the internet to a computer that is hosting the files/information for your website. Because of the nature of web servers each website does not need it's own unique ip address ( unless you are using https/ssl certificates ).