Cyber-bullying (predominantly spelled cyberbullying by many researchers) is when someone repeatedly makes fun of another person online or repeatedly picks on another person through emails or text messages, or uses online forums and postings online intended to harm, damage, humiliate or isolate another person that they don’t like.

 Check out this video about Cyberbullying

The National Crime Prevention Council criterion of what constitutes cyber-bullying is "when the Internet, cell phones, or other devices are used to send or post text or images intended to hurt or embarrass another person."

Online bullying, called cyberbullying, happens when teens use the Internet, cell phones, or other devices to send or post text or images intended to hurt or embarrass another person. Cyberbullying researchers Hinduja and Patchin define cyber-bullying as: "willful and repeated harm inflicted through the medium of electronic text" and recently updated the definition to account for cyberbullying through the internet that occurs without actual text, such as videos being uploaded to YouTube, for example.

The updated definition as awareness of the phenomenon increases is: "the intentional and repeated harm of others through the use of computers, cell phones, and other electronic devices."

Cyber-bullying can be as simple as continuing to send e-mail to someone who has said they want no further contact with the sender, but it may also include threats, sexual remarks, pejorative labels (i.e., hate speech), ganging up on victims by making them the subject of ridicule in forums, and posting false statements gossip as fact aimed at humiliation.

Cyber-bullies may disclose victims' personal data (e.g.m real name, address, or workplace/schools) at websites or forums or may pose as the identity of a victim for the purpose of publishing material in their name that defames or ridicules them. Some cyberbullies may also send threatening and harassing emails and instant messages to the victims, while other post rumors or gossip and instigate others to dislike and gang up on the target.

Though the use of sexual remarks and threats are sometimes present in cyber-bullying, it is not the same as sexual harassment and does not necessarily involve sexual predators.

Cyber-bullying vs. cyber-stalking

StopCyberbullying.org, an expert organization dedicated to internet safety, security and privacy, defines cyberbullying as:

"a situation when a child, tween or teen is repeatedly “tormented, threatened, harassed, humiliated, embarrassed or otherwise targeted” by another child, tween or teen using text messaging, email, instant messaging or any other type of digital technology."

The practice of cyberbullying is not limited to children and, while the behavior is identified by the same definition in adults, the distinction in age groups is referred to as cyberstalking or cyberharassment when perpetrated by adults toward adults. Common tactics used by cyberstalkers are to vandalize a search engine or encyclopedia, to threaten a victim's earnings, employment, reputation, or safety.

A pattern of repeated such actions against a target by and between adults constitutes cyberstalking.