protocol://serverName URI
e.g., http://www.csc.liv.ac.uk/~martin/index.html
To retrieve a document via HTTP from the server, we can issue a GET request using the HTTP protocol
GET URI HTTP/1.1
Host: serverName
Web server only knows the contents of the GET request message
- this request is automatically generated by browser when you select a URL
- could also come from a link checker, a search engine robot, …
- can come directly from a telnet connection using port 80