Nonverbal communication is the transmission of messages or signals through a nonverbal platform such as eye contact, facial expressions, gestures, posture, use of objects, and body language. It is the process of sending and receiving messages without using words, either spoken or written. Nonverbal communication can play five roles: repetition, contradiction, substitution, complementing, and accenting. It can portray a message both vocally and with the correct body signals or gestures. Body signals comprise physical features, conscious and unconscious gestures and signals, and the mediation of personal space. Nonverbal communication is a rapidly flowing back-and-forth process that requires full focus on the moment-to-moment experience. Some examples of nonverbal communication include facial expressions, eye contact, gestures, posture, tone of voice, and touch. Nonverbal communication is a powerful tool for achieving many kinds of influence, including perceptions of power, attraction, empathy, deceit, and rapport.