Kink is about pleasure and enjoyment, building one another up to be the best they can be. Kink requires respect, communication, honesty and trust to keep it safe and pleasurable for all those involved. Kink requires all these with negotiations for use to make safewords, acknowledge and respect limits. Without all this it becomes dangerous for all participants involved.
Abuse is when someone does not respect, accept and listen to your limits, and not accepting your safe word or stopping when it's used, or they do not offer aftercare. These are huge red flags to be mindful off. Abuse is also when something that happens that you have not consented to, consent is everything in kink.
Both dominants and submissives can be abused or abusive so please be mindful of this. This is why vetting is important from both dominant and submissive roles and slowly building the dynamic and not rushing so. You can get to know and see who you are really connecting with. This also helps to ensure your physical and mental well being when doing play sessions or scenes. Abuse can also develop later on in a dynamic remember consent is everything