Once, the only means of communication—the only channel—was face-to-face contact. But as society became more sophisticated, other channels emerged. Smoke signals, handwritten correspondence, telegraph, telephone, e-mail, and text messaging are all examples. A channel is simply the method through which communication occurs. We must have a channel to communicate.

Most people in technologically advanced societies use many channels to communicate, though they are not always proficient at adapting communication for the channel being used. Do you have a friend who leaves five-minute voice-mail messages on your cell phone as though speaking directly with you? Or do you have a cousin who shares deeply private information with all six hundred of her Facebook “friends”? We all need to identify the channel that will work best for certain messages, at certain points in our relationships with certain people, and then adapt our messages to that medium.