There is only one lightsaber that was passed on from Anakin to Luke, and that is the lightsaber that Obi-Wan took from Anakin at the end of "Revenge of the Sith" and gave to Luke in "A New Hope", which Luke then lost at Cloud City in "The Empire Strikes Back".
We do not (yet) know the story of how the lightsaber ended up in Maz's pocession after that:
MAZ
I've had this for ages...
MAZ'S CASTLE - TREASURE ROOM - DAY
Maz opens the box -- holds out the lightsaber to Finn:
MAZ
Kept it locked away.
HAN
Where'd you get that?
MAZ
**A good question for another time.**
(TO FINN)
Take it! Find your friend!
To compare, you can see Luke receive Anakin's lightsaber in this scene:
And here's a clear image of Maz Kanata handing the same one to Rey:
