HTTP header information

I am just looking at some old exam papers for an exam I have tomorrow and I know the answers to the majority of the questions (hopefully!) but I am not sure about how to put them, i.e how HTTP functions, what is sent, when and where. Would anyone be able to point me in the direction of somewhere I could learn about this, or possibly explain it here ?

The questions we are getting are of this style :

Ten HTTP requests arrive at port 80 on IP address 192.168.0.0; state what the contents of the response body will be, in particular give the absolute pathname of the file,if any, that will be served in the response body; and explain in detail why this response body will be served.

I am able to work out what the contents should contain, but I am not sure how HTTP structures the information, I know how to work out the absolute pathname of the file I think, is the re开发者_如何学JAVAsponse body just the contents of the HTTP packet being sent back to the client ?

Thanks a lot for the help with this.

The response body is the information part of the packet that is sent. The packet as-is contains more information then that. You can look it up here: http://en.wikipedia.org/wiki/IPv4#Packet_structure

I believe the response body you mention refers to the "data" part of an http packet.

I do not see why there -has- to be an absolute filename involved. If it is a http file request the absolute file name would depend on so many things (which server is being used, which config etc.) I do not see how there can be a general answer to this. The question is very strange - what if there is not even a webserver installed? :P And the response most definately depends on what kind of server is running, what modules are installed etc. wihthout that information and what the requests actually are it seems difficult to answer the question.