If the vehicle has only four wheels, I'd say they are the same. However, if the vehicle has more than four (and I don't mean doubling up as in a truck)then an AWD could be more than a 4WD. For example, the old Blitz Wagon with about eight drive wheels on the ground.
This term, AWD didn't exist thirty years or so back. The four-wheel drive vehicle was a designed for off-road conditions. The Land Rover, the Jeep, the Toyota Landcruiser. Then the manufacturers started coming up with ridiculous phrases like '2 by 4'. Which means an ordinary two-wheel drive, either rear or front wheel drive.
There might be a subtle difference. Some 4WD can be made into 2WD by switching out the second set of drive wheels (This was for economy) I think an old 1960s long wheel base Land Rover I used to drive occasionally had that feature. But technically, it would be referred to as a four-wheel drive vehicle not a AWD.