Answer:   Request handling can usually be broken down into a series of independent steps. Each step might depend on additional information being available about the request, so order does matter. However, the individual steps are separable. For example, a typical request might go through these steps:
1. Compare the request URI against a list of restricted directories, to make sure that the user has permission to access the specified directory.
2. Translate the request URI into a real file name, taking index files into account when the file name refers to a directory.
3. Given the file name’s extension, determine the MIME type of the file.
4. From the MIME type, dispatch the request to the appropriate handler.
This is only one of many possible request-handling configurations. Other configurations might dispatch based on a beginning path such as /cgibin. Other configurations might move the session-tracking step to be performed only for files with the MIME type text/session-tracked.