How is kink different from abuse?

This is a totally fair question. 

After all, many mainstream media depictions (including porn) give the impression that the person “in charge” of the scene or relationship (usually the top, dominant, master, or owner) has all of the power, and the other partner(s) are helpless, having waived their right to say “No,” or reject orders. 

In the words of the famous commercial, “That’s not how this works. That’s not how ANY of this works.” 

Find the transcript for this episode here. BDSM vs. Abuse - Dating Kinky