|I am not able to clarify what is MPLS VPN and VPN over broadband|
You can't have tried.
Google is your friend, try using it.
We're not going to give you answers to things you can easily find out with a couple searches. I'll give you a hint to get you started, look up the meaning of the acronyms in an online acronym dictionary or an online computing dictionary.
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.