Erving Goffman, the founder of that theory, is using terms such as stage, role, façade or ensemble in his publication. Based on these metaphorical terms, he explains the self-exposing behavior of individuals and describes how people tempt to take control of their personal presentation.
If people face other people, they intend to gain information, that are qualified to evaluate the personal character of that other person at the one hand and to provide information about themselves in order to show a particular self-image. Sources to evaluate the personality traits of someone can have several forms. For instance is it possible to analyze the articulation of a person, the tone of the voice and even the body language. However, related to social networks, its literally not possible to notice someone else body language since users are most likely not right next to the observer.