What is Labial sounds?

Labial sounds: The lips are not only anatomic features of note, they are organs of speech essential to certain articulations. A sound requiring the participation of one or both lips is a labial (labium in Latin means lip) sound or, simply, a labial. All labials are consonants. There are bilabial sounds such as p which involve both lips and labiodental sounds such as v which involve the upper teeth and lower lip.