Communication, the process of sharing ideas, information, and messages with others in a particular time and place. In every society, humans have developed spoken and written language as a means of sharing messages and meanings. The most common form of daily communication is interpersonal-that is, face-to-face, at the same time and in the same place. The most basic form of interpersonal communication is a dyad (an encounter or conversation between two people). Communication may also occur in small groups, such as families, clubs, religious groups, friendship groups, or work groups. From the earliest times, people have needed to communicate across distance or over time. Since the beginnings of writing, communication media have allowed messages to travel over distance and time. As more books became available, more people learned to read.

Printers published other things besides books, including newspapers, pamphlets, and broadsides. Different societies have also devised systems for transporting messages from place to place and from person to person. The earliest were courier-type services; messengers carried memorized or written messages from one person to another, and returned with the reply. The first truly electronic medium was the telegraph, which sent and received electrical signals over long-distance wires. The telegraph and telephone were systems for distance communication that sent electrical signals through wires.