If you have read your fairy tales, you would know that trolls are generally grotesque creatures that stay away from human habitation. They take pleasure in carrying out antisocial activities and causing people pain and mental suffering.
Those trolls are mythical, but the online trolls are very much real. These digital trolls use the anonymity offered by the net to stay hidden and cause disruption and harm through their malicious and negative comments. They share provocative, malicious content and delight in fomenting unrest. If the victim takes the comments personally, it can leave them emotionally disturbed.