Emotion Recognition: The ability to identify and perceive others' emotions, which is something that Ekman's research greatly contributed to.
Microexpressions: Brief, involuntary facial expressions shown on the face of humans according to the emotions being experienced. They are often unnoticed but provide cues about emotion if detected. This concept was extensively studied by Ekman.
Nonverbal Communication: The process of conveying a message without the use of words either spoken or written. It includes gestures, body language, facial expressions etc., all areas where Ekman's research has been influential.