Dyadic communication occurs when two people are conversing directly to one another. It is a form of interpersonal communication that refers to the quantitative quality of a communicative relationship between two people.
Dyadic communication is also interchangeably referred to as interpersonal communication. There are also many other types of communication corresponding to quantitative and qualitative definitions.
Dyadic communication can be further defined by its qualitative characterizations, namely how interpersonal it is. Because of this, some dyadic communications can be personal or intimate in their nature while other forms of dyadic communication can actually be impersonal.
There are other terms associated with dyadic communication like "communication competence." This term applies to communication that is effective and appropriate. Communication between two people can have competence based upon the situational context that takes place. Dyadic communication can have competence depending largely on the culture in which it takes place, as well as the nature of the relationship between the two people communicating with one another. Competence can also be learned.
On the opposite end of this spectrum, some communication between two people can have no competence, at all. This kind of communication does not help the people involved and disproves the notion that more communication is always better. Communication between two people doesn't have to be aimed at understanding, either. In numerous social contexts, communication between two people oftentimes is aimed around the motives of deception or ambiguity.