As far as I'm concerned, based on the NOW common usage of words...
Pocket = The basic necessities of the music. Nothing more or less. A drum machine can do this, and you don't have to pay them.
Groove = Why you hire musicians, and the reason why drum machines won't replace drummers completely. Well, at least not in the forseeable future, lol. I think it's safe to say, if your playing doesn't 'cause someone to want uncontrollably/unknowningly move to the music - it/you ain't grooving.
So many drummers are being asked to play the bare necessities, because they can't handle the freedom. I frankly believe, in many cases, the only reason drummers are up on stage is because it goes against tradition to have a band without a drummer on stage. For appearances only...
Bump all this crap. Let's get back to music that moves - not only within itself, but moves people. Everything is too linear, and drummers, and other musicians, come across as really stale/sterile/stupid, lol....