As such the term 'wider' means the 'reachability'? I think you meant to say the Application or ServletContext as Context here.
As such the application scope is within the environment it lives across all the sessions. It is basically tied up with the container's execution not the user's. Whereas Session is basically for the continued activity of one user. In a single environment, ServletContext or Application has a wider scope.
In a distributed environment, i guess 'session' can have more scope as it can be shared across the JVMs. Not very sure about the Application Context.
[Corrected the term JRE as JVM] [ June 25, 2008: Message edited by: Raghavan Muthu ]