More Predefined Variables
An object of type ServletContext object associated with the application. Like HTTPSession, this can cache values. Unlike HTTPSession, the stored values are shared by all servlet invocations in the current “application” (which typically corresponds to the servlet context).
The ServetConfig object associated with this page (see, for example, the discussion of initialization parameters in the lectures on servlets).
An object of type PageContext . Something like ServletContext, but values stored here are only shared by invocations of this page. Thus very similar in behavior to servlet instance variables.