This week's book giveaways are in the Refactoring and Agile forums. We're giving away four copies each of Re-engineering Legacy Software and Docker in Action and have the authors on-line! See this thread and this one for details.
A ServletConfig object is used to serve initialization info to the Servlet. A ServletContext object is the one that's used by the Servlet at runtime to dynamically get handle to other context resources/objects. Both serve two different purposes.
You can theorotically, get a RD object from config too (see below), though it would actually access the context object for this