The communication process has three main elements: the sender, the message, and the receiver. The sender's credibility and background relative to the message can affect the receiver. Differences between sender's and receiver's experiences and attitudes are also important in how a message is received. The words that comprise messages and the tones used to express them can vary the meaning and interpretation of messages. People differ in their susceptibility to persuasion. Emotion has an effect in persuasion but more important are the order of presentation and the believability and effectiveness of the sender. Those who know how to listen and pay attention not only stand out as beacons of courtesy but also have an advantage — by understanding what is expected of them — in preparing their messages for others.