Communication is the process of understanding and sharing meaning between individuals through symbols, signs, or behaviors. There are three main types of communication: intrapersonal (within oneself), interpersonal (between individuals), and public (with a group). Social work communication is a purposeful process that allows information gathering to assess a client's problem and enact an intervention. The key elements of communication are the source, message, channel, and receiver. Effective social work communication involves congruent verbal and non-verbal messages that are simple, specific, intelligible, and sufficiently repeated to reduce noise. Problems that can arise include double messages, ambiguity, referent confusion, overload, and order incongruence.