Tactics can have the following meanings:
- The reading of move sequences, their variations and related decision making, and the related skills.
- The techniques used in (often local) fights and the skills you need to bring them to a good end.
If the first meaning is used tightly as 'reasonably complete tactical reading', 'tactics' is the complement of strategy. The second meaning is usually known under the name 'techniques'.
A local move with a large benefit is called a strong move.
The planning and decision-making based on incomplete information about the details of variations and related decision-making, and the skills for thinking globally are called strategy.
Authors: Dieter Verhofstadt, Jared, Robert Jasiek
See also Chess tactics as defined on wikipedia