Abuse is a pretty common term - most people have some experience with being both the abused, and the abuser.
The common idea is that it's one-sided. One person is the victim, and the other is just sick, damaged, broken, evil. But there is no such thing as a one-way abusive relationship. In any relationship that you call abusive, both people are hurting the other, and both people are giving the other what they want. If they were not giving that which you might call abuse, the other person would be unhappy, or bored, or unsatisfied, and just leave. It goes both ways.
With this understanding, those who have been in abusive relationships, can begin to forgive themselves. You were not the bad guy, both of you were abusive. And if you have been abused or feel like a victim in some way, you can understand that if you are in a relationship and feel like a victim, you are both abusing one another. And if you live in fear of having a relationship, for fear you'll be abused or repeat your parents mistakes and become abusive yourself, perhaps you can let go of some of that fear.
There's the idea that everyone out there are happy innocent people, and sometimes a bad person comes through and ruins everything. It doesn't work this way. For example, almost every rape out there starts with a question, like "Do you know what time it is?" Someone who is looking to be treated badly, will answer in such a way that the other asks something else. There is not a moment of someone jumping out and dragging you in a van, that's very rare. It's a negotiation, and if two people slot together in what they want, the abuse happens. Once you draw a line and say no, the abuse stops.
Withholding something that the other deeply needs, is also abuse. Abuse does not come out of nowhere. It always goes both ways. You may not realise it, but always both parties are being hurt. And both parties are getting something out of it.