Great Move vs Best Move

In terms of strength of the move, is there a difference? Seems to me great move (move that altered the course of the game) classification is more based on the effect the move has on the game e.g. taking advantage of opponent blunder is classified as a great move but is also a best move (chess engines top choice).

Am I thinking of this right?

'Great' or 'best' moves do not exist, there are only good moves, mistakes (?) and blunders (??).
All chess games end in either a draw, a win, or a loss in a finite number of moves. Hence all chess positions including the initial position are either draw, won, or lost.
A good move does not change the objective evaluation.
A mistake (?) changes the objective evaluation from draw to lost or from won back to draw, i.e. missed win.
A blunder (??) or double mistake changes the objective evaluation from won to lost.