Bullying can be described as the intentional hurting of a person or people by another person or group on a regular basis, resulting in the creation of a one-sided power relationship. Bullying can take many forms, including physical violence, verbal abuse and psychological abuse. Bullying can be done in-person, or via other means, e.g. on social media or the internet (known as cyberbullying). Cyberbullying takes bullying out of the classroom or the school playground and follows the victim home, resulting in 24-hour-a-day abuse.

Although a lot of research focuses on school children, it is important to remember that bullying is not unique to children. Adults can be bullied and bullies to adults or children. This guide focuses on research into bullying of and by younger adults and children. Also included is a section showing statistics on adult bullying in the workplace.