See: Page, Request, the session and application What is the difference?
1. Briefly page refers to the current page. Jsp pages in a valid
2.request refers http request to the server from the end of the processing, the process returns a response. Skip forward manner plurality jsp used in the process. In these pages you can use this variable.
3.Session effective range of the current session, open the browser from the browser to shut down the process.
4.application its effective range is the entire application.
Scoped variables in their survival time is the longest, if not manually deleted, they have been able to use
