httpmodule

hi; 

what is difference between httpmodule and httphandler?

Thanks,mohsen

A module runs in the background of the Web Site (or can run in the background of
the server in IIS 7) and can do many things. Primarily they are used to catch
the request by assigning event handlers for difference events in the ASP.NET
pipeline. For example it is really common to write a URL Rewritter as a custom
httpModule.

An httpHandler actually processes the request either directly or by being
assigned to a file extensioin. ASP.NET .aspx pages, for example, are actually
executed through a customized handler. A very common example of using
httpHandlers is to stream custom images on the fly. Many times they will do the
resizing at run-time, other times they can be used to protect documents from
unauthorized access, etc. 

Watch my geekSpeak on the topic to get a visual on how they differ.

http://channel9.msdn.com/ShowPost.aspx?PostID=362964