Cyberbullying is the use of technology to harass, threaten, embarrass, or target another person. Online threats and mean, aggressive, or rude texts, tweets, posts, or messages all fall under Cyberbullying.
Cyberbullying also includes photos, messages, or pages that don't get taken down, even after the person has been asked to do so. In other words, it's anything that gets posted online and is meant to hurt, harass, or upset someone else.