This paper describes a multidimensional activity approach to communication. One of the goals of the approach is to clarify some of the relations that exist between cognition and communication, in terms of the degrees of awareness, intentional control, speed and types of content that occur in communication. Another goal is to describe and clarify some of the relations between communication and joint activity. This is done through the notions of “coactivation” and “social activity”. The paper provides a definition of communication and includes a criticism of the “turn taking” model of communication, in favour of a view of communication as a multidirectional flow of information. There is also a sketch of communication as coactivation of meaning potentials, through the use of semantic-epistemic operations.