LEGALLY, it's whatever your local authorities say it is.
ACTUALLY...and this is just my opinion...it is ANYTHING you do to attract deer, PERIOD! I don't care if it's a salt lick, a doe decoy, CREATING a funnel, planting food plots, using scents and sounds...WHATEVER. To me, it's all the same. The point is to lure deer into coming to you by ALTERING what would naturally occur IF YOU WEREN'T THERE.
Now, I'm not saying one way or another that there is a problem, or not, with any of the above. I'm just saying they are ALL a means to the same end.