The document defines nonverbal communication as communication without words, including facial expressions, gestures, body language, and tone of voice. It discusses how Professor Mehrabian found that communication is 7% verbal and 93% nonverbal, with body language and tone of voice making up the nonverbal component. The document also lists several types of nonverbal communication, such as eye contact, gestures, and personal appearance, and discusses benefits like reinforcing messages and regulating conversation, as well as disadvantages like emotions being visible and lack of permanent records.