Difference between tactic and combination? What is the difference between a Tactic and a Combination?  For reference, here is a game I played as white and I think I had a nice combination from move 16, but I am not sure if it is classified as a combination or tactics.  This what my thought process from move 16 was.  There are probably multiple mistakes made in the game, but I am not looking for a complete analysis.

16. Bc2 - staring down the diagonal
17. Ned4 - I am hoping he will take it so I can advance my pawn to e5.
18. exd4 - He takes the sacrifice which is what I was hoping for.
19. Qxh7# - Apparently, he didn't notice the open diagonal and probably was concentrating on me attacking his bishop.

[FEN ""]
1. e4 d6 2. Nf3 g6 3. d4 Bg7 4. Be3 Nc6 5. Bb5 Bd7 6. O-O e5 7. d5 Nce7 8.
   Qd3 a6 9. Bc4 b5 10. Bb3 f5 11. Nc3 f4 12. Bd2 Bf6 13. a3 Nh6 14. Ne2 g5 15.
   c4 O-O 16. Bc2 Qe8 17. Ned4 exd4 18. e5 dxe5 19. Qxh7#
The United States Department of Defense Dictionary of Military Terms defines the tactical level as:


  The level of war at which battles and engagements are planned and
  executed to accomplish military objectives assigned to tactical units
  or task forces. Activities at this level focus on the ordered
  arrangement and maneuver of combat elements in relation to each other
  and to the enemy to achieve combat objectives.


Your ultimate combat objective is to checkmate, and for that you'll have to assign specific tasks to the tactical units you have deployed in order to achieve the desired objective.

For example:

17. Ned4 - Tactical sacrifice, in order to allow e4 pawn to advance.

18. e5 is merely the completion of the tactical maneuver.

From the moment you are considering the diagonal b1-h7 as one of your attacking strengths you are considering a "strategy" which is to checkmate on h7, or in other words you are considering the "combination" of the specific techniques (tactics) involved in accomplishing such objective.