Online roleplay
Online roleplay is the art of creating fictional stories in real time by two or more individuals connected through the internet. The players assume character roles and interact with each other (commonly in text only) with the purpose of generating emotional responses in the other roleplayers.
In other words, roleplaying is acting a character, the same way actors perform in a movie or on stage. However, in online roleplay the actors have more creative control because the story is developed on the go instead of being previously scripted. Improvisation makes roleplaying even more interesting, since the roleplayers do not know how the story will turn out.
In the "roleplay world" physical and social laws and other limitations can be defined by the roleplayers themselves. The setting and tone of the story can be discussed on beforehand by the roleplayers so the behavior of their characters can be attuned.
Origin
As with many online activities, roleplaying originated in the offline world. Most children roleplay to use their imagination and allow them to imitate adult activities.
The famous childhood game of "playing doctor" is probably the first kind of roleplay most of us practiced, serving the purpose of coping with the fear of being examined by a doctor by turning it into a game, and also as a means of exploring each other's bodies and sexual experimentation.