HTTP/URL research exercises

Research online what the following are and what they do:

• The fragment part of a URL.
• The Accept header sent by the HTTP client.
• The User-agent header sent by the HTTP client. What does your browser send?
• How do you encode a path that contains a space in an URL? Which other characters are "special" and need to be treated this way in paths?
• Which web server is the University of Bristol using for www.bristol.ac.uk, according to the headers? Read up online on this server and the organisation of the same name that maintains it.