A conversation is an exchange of thoughts and ideas between two or more people. An instance of focused interaction, a conversation occurs when people co-operate with each other to introduce and sustain a single focus of attention by taking turns talking with each other. Conversations are the most natural, most frequent, and most universal of all forms of spoken language. Generally restricted to small groups, conversations involving larger groups tend to divide into several conversational groups. For example, even groups as small as four people tend to separate into two dyadic units.