There are three major forms of bullying: Physical, Verbal, and indirect.
I will list the definition of each, and have two examples per category.
One where the victim isn't assertive, and one where they are
Physical Bullying is when someone uses their body to hurt someone.
It can range from bumping into them to shooting them.
This is the classic form of bullying.
Verbal Bullying is when someone offends someone else with words.
It can be anything from Blackmail to name calling.
This is a common form of bullying.
Indirect Bullying is when someone spreads misinformation about someone else.
It may not be intentional, as with someone spreading a misheard story. This is a hard one to recover from, and unfortunately very common.