Communication requires a sender, a message, and a recipient. It serves several functions including meeting basic needs, exchanging information, maintaining social routines, and fostering closeness between people. There are different modes of communication that can be used, including pictures, signs, gestures, voice output devices, and other alternatives to speech. Effective communication involves determining the individual's preferred mode, using consistent language, allowing multiple responses, and providing prompts on a continuum from least to most intrusive.