For the qualification of movement there are four common terms: mechanics, technique, form and style. I use both technique and form somewhat interchangeably, although there is a slightly nuanced distinction.
Mechanics are anything that deal with the physics. When I talk about angular velocity, momentum, leverage, origin or insertion of muscles, torque, force, power, relative angles, we are talking about mechanics.
Technique is the method for completion of a movement. It includes the mechanics, but moreso answers the question, “How do you complete the movement without the physics?” For example: pull, let go, look, arm up, turn, shoulder drop, etc.
Form is when you insert an adjective to the movement. That was a “good” arm pull; or, “you shouldn’t” lift up your head. You can apply form to both the mechanics and technique of a movement.
Style is essentially your signature to a movement; that is, that aspect of the movement that is fairly unique to you. The best coaches could watch the silhouette of their athlete move and tell you who it is. Style does not enter into the normative assessment, is not important to technique, and does not alter substantially the physics.
For more on this topic, watch this video: