When we communicate with one another face to face, nonverbal communication is very important to our ability to make ourselves understood. This is one of the major problems with online communication. In the online environment, we do not have good ways to communicate nonverbally. People cannot hear our tone of voice. They cannot see our gestures. They have to rely on our words alone. This can lead to misunderstandings, particularly about when we are joking or not.
Partly in response to this, we have developed a few techniques for nonverbal communication in the online environment. Perhaps the most common of these techniques is emoticons. We use things like :-D to show that we mean something to be amusing. We also use things like writing a word in all capital letters to show that we are shouting. We can put an asterisk on each side of a word to emphasize it, much as we might put a word in bold print or italic type.
In these ways, we can achieve some degree of nonverbal communication even online. However, it is not as rich as the nonverbal communication we have in face to face conversation.