Difference between ServletContext and ServletConfig

ServletContext Defines a set of methods that a servlet uses to communicate with its servlet container.
ServletConfig is a servlet configuration object used by a servlet container used to pass information to a servlet during initialization. All of its initialization parameters can ONLY be set in deployment descriptor.
The ServletContext object is contained within the ServletConfig object, which the Web server provides the servlet when the servlet is initialized.
You can specify param-value pairs for ServletContext object in tags in web.xml file.
The ServletConfig parameters are specified for a particular servlet and are unknown to other servlets.
The ServletContext parameters are specified for an entire application outside of any particular servlet and are available to all the servlets within that application.