A lock-off 2BR is comprised of a 1BR and studio connected by a door between the two- which, when unlocked serve to offer the same amenities as a dedicated 2BR.
The lock-off will have two entrances, a full kitchen, plus a mini kitchen in the 2nd bedroom and also a balcony off that same room. The dedicated 2BR will have a single entrance and only 1 balcony.
Some, with small children, prefer the dedicated villa, with no 2nd exterior doorway for the children to worry about.
Both are great accommodations.
Enjoy!