It is the portion of the swing or stroke after impact with the ball until the end of the swing. We often underestimate the value of the follow-through since the ball has already been struck.
In reality, it presents the complete picture of the impact on the ball. The momentum we carry through the motion is indicative of the quality of the strike. We expect quality strikes to carry the momentum through the impact in a specific way.
When this is absent, the strike is incomplete and the trajectory of the ball is affected.
A new decade has just been struck. We got the ball moving.
The quality of the strike is as much dependent on a good start as it is a good follow-through.
Complete the swing.