Host and service identification
The next part of the HTTP URL identifies the host on which the web server is running, and the port on which the server listens for HTTP requests. The domain name or the IP address can identify the host component. Using the domain name allows user-friendly web addresses such as:
http://www.w3.org/Protocols/
The equivalent URL using the IP address is more difficult to remember:
http://18.29.1.35/Protocols/