What is the difference between getRequestDispatcher () of ServletContext and ServletRequest

Please explain in easy to understand language and explain with a simple working example.

Please explain from latest J2EE version.

I want to understand when to use ServletContext and when to use ServletRequest's dispatcher call

From Javadoc

The servletRequest's getRequestDispatcher() can take a relative path while
ServletContext's getRequestDispatcher() can not(can only take relative to the
current context's root).

For example
with ServletContext both
-> request.getRequestDispatcher("./jsp/jsppage.jsp") - evaluated relative to the path of the request
-> request.getRequestDispatcher("/jsp/jsppage.jsp") - evaluated relative to the root
are all valid
 
with ServletContext only
-> context.getRequestDispatcher("/jsp/jsppage.jsp") is valid
but not context.getRequestDispatcher("./jsp/jsppage.jsp").
that is it can not evaluate a path other than context root.

As said in Javadoc servletContext's requestDispatcher must begin with a "/" and is interpreted as relative to the current context root.

Hope this helps,
Krishna

thanks for the help Sravi