Phonetics is the study of sound in speech; phonology is the study (and use) of sound patterns to create meaning. Phonetics focuses on how speech is physically created and received, including study of the human vocal and auditory tracts, acoustics, and neurology. Phonology relies on phonetic information for its practice, but focuses on how patterns in both speech and non-verbal communication create meaning, and how such patterns are interpreted. Phonology includes comparative linguistic studies of how cognates, sounds, and meaning are transmitted among and between human communities and languages.