Verbal and nonverbal communication are part of the complete interaction process and, in practice, inseparable. For research purposes, verbal and nonverbal communication can, however, be looked at as distinctive objects of study. Verbal communication, i.e. what is being said or written, has traditionally been the focus of linguistics. Nonverbal communication, i.e. how something is being said or written or done, is one of the focuses of communication sciences.
In the field of intercultural communication, Edward T. Hall was the first scholars to carry out systematic empirical studies and classification of nonverbal communication. He also emphasized the out-of-conscious level of information exchange. Hall defined nonverbal communication as communication that does not involve the exchange of words.