Throughout history there has been 3 main forms of bullying:
Physical
Non-Physical Verbal
Non-Verbal
The above can be either direct or indirect.
Below in the table there is a classification of the forms of bullying which was found in Rigby, (1996, p. 20):
Although the above three forms are the main forms of bullying , there are also sub forms of bullying which include racist bullying, sexual bullying, bullying of special needs children, sexual preference (Sullivan, 2000) and the form that has become more common; cyber bullying (Trolley & Hanel, 2010).
References:
Rigby, K. (1996). bullying in schools and what to do about it. Melbourne, Victoria: The Australian Council for Educational Research Ltd.
Sullivan, K. (2000). The Anti-Bullying Handbook. Auckland, New Zealand: Oxford University Press.
Trolley, B, C. & Hanel, C. (2010). Cyber Kids, Cyber Bullying, Cyber Balance. United States of America: Corwin.
[Photograph]. Retrieved July 28, 2015, from http://www.google.com/image