I am not sure of what you are asking.
I guess this can help:
A ServletConfig is "A servlet configuration object used by a servlet container to pass information to a servlet during initialization." ServelConfig can be used to get servlet specific initialization parameters configured in Deployment Descriptor.
A ServletContext: "Defines a set of methods that a servlet uses to communicate with its servlet container, for example, to get the MIME type of a file, dispatch requests, or write to a log file. There is one context per "web application" per Java Virtual Machine."
All servlets have access to one servlet context which also can have init parameters. Also you can set attributes which can be an Object, in a servlet context, but not in a servlet config.