This document discusses body language and its importance in communication. It defines body language as nonverbal communication through physical behaviors like posture, gestures, facial expressions, and eye movements. The document notes that research shows body language accounts for 50-70% of communication. It categorizes body language by intent (voluntary vs involuntary movements) and identifies some examples like crossed arms indicating defensiveness or nail biting showing stress. Tone of voice is also discussed as a separate form of nonverbal cues.