Bullying is the use of force, coercion, hurtful teasing, comments, or threats, in order to abuse, aggressively dominate, or intimidate one or more others. The behavior is often repeated and habitual. One essential prerequisite is the perception (by the bully or by others) that an imbalance of physical or social power exists or is currently present. This perceived presence of physical or social imbalance is what distinguishes the behavior from being interpreted or perceived as bullying from instead being interpreted or perceived as conflict. Bullying is a subcategory of aggressive behavior characterized by hostile intent, the goal (whether consciously or subconsciously) of addressing or attempting to "fix" the imbalance of power, as well as repetition over a period of time.
Bullying can be performed individually or by a group, typically referred to as mobbing, in which the bully may have one or more followers who are willing to assist the primary bully or who reinforce the bully's behavior by providing positive feedback such as laughing. Bullying in school and in the workplace is also referred to as "peer abuse". Robert W. Fuller has analyzed bullying in the context of rankism. The Swedish-Norwegian researcher Dan Olweus stated that bullying occurs when a person is "exposed, repeatedly and over time, to negative actions on the part of one or more other persons", and that negative actions occur "when a person intentionally inflicts injury or discomfort upon another person, through physical contact, through words or in other ways". Individual bullying is usually characterized by a person using coercive, intimidating, or hurtful words or comments, exerting threatening or intimidating behavior, or using harmful physical force in order to gain power over another person.