what is Render body,Render Page,RenderSection ?

hi frnds,

 

    I am Beginner in Asp.net Mvc I have the Doubt for these three topics ,,Please if you know these means tell me What is Render Page,Render body,Render Section..why we use this please share your Knowledge and share some related Links

 

 

  And share me this Too..What is ViewData and ViewBag ...?