The pageContext object is an instance of a javax.servlet.jsp.PageContext object. The pageContext object is used to represent the entire JSP page.
This object stores references to the request and response objects for each request. The application, config, session, and out objects are derived by accessing attributes of this object.
The pageContext object also contains information about the directives issued to the JSP page, including the buffering information, the errorPageURL, and page scope.