Light
Human expressions refer to the various facial movements and gestures that convey emotions and communicate nonverbally. They include smiles, frowns, raised eyebrows, and other facial cues.
Internal states that motivate behaviors and are accompanied by physiological changes. (e.g., happiness, sadness)
Nonverbal Communication: The transmission of messages or information through facial expressions, body language, gestures, etc.
Microexpressions: Brief facial expressions that occur involuntarily and are often difficult to detect.