Body language is an important form of non-verbal communication that reveals people's true feelings and impacts the message being conveyed. It allows people to understand each other by reading body language cues and matching them to spoken words. Mastering body language can help with persuasion, understanding what others are saying, and navigating day-to-day social interactions. Some key aspects of body language include facial expressions, eye contact, posture, gestures, and physical positioning and movement.