Reg: Difference between chroot & pivot_root

[Alphonse Hansel Anthony <alphonse.anthony@xxxxxxxxx>]

Hi,
   What is the difference between chroot & pivot_root. 
   They don't seem obvious based on the man pages apart from the below mentioned
   caveats.

   1) Inherited Open file descriptors, have to be explicitly closed.
   2) Does not change CWD of the process, which can be overcome by doing a chdir before & after chroot call.
   
   Any information on this would be useful.
   
Thanks,
Alphonse