Abusive power and controlling behaviour are the tactics used by an person to gain and maintain control over another person to manipulate him/her. The abuser could be anyone, parents, teachers, romantic partner, spouse or someone who is of socially higher power.
These tactics are meant to undermine your self belief and confidence. The abusive person tries to make others feel ashamed of your weaknesses. The abusive behavior of the abuser creates an environment of hierarchy in which they are superior to others. They always tend to place their emotional needs ahead of others.
The abusers deny the problem and claim that they can't control themselves. This is a false theory. Notice that they are not abusive to their superiors, because there would be consequences to that behaviour. They blame their abusive actions on others and imply that it is other people that need to change.
The abuser's behaviour leads to development of codependency in a relationship in which a person despite being deprived and unhappy accepts his/her fate but fears alternatives.