Communication devices are any devices which aid in the process of communication. Types of communication devices can range from communication aids, like a picture board, to electronic communication, like email.
Runners and homing pigeons are examples of early forms of communication devices. As time passed and technology evolved, faster, more efficient communication devices were created.
Communication devices are separated into types based on the direction of communication. A communication device which only allows for communication one way, like a radio broadcast, is known as simplex. A phone conversation, in which there is communication back and forth but not at the same time, is known as the half duplex system. Communication devices which allow for simultaneous interaction are full duplex systems.
Communication aids are communication devices which give people who have trouble speaking verbally the ability to communicate with others. People with disabilities are likely to use communication aids. An example of a communication aid is a picture board which uses pictures to communicate ideas.
Social networking websites, instant messaging, and email are examples of electronic communication. Email is the most commonly used form of electronic communication. Many educational institutions rely on email to communicate information to a large mass of people.
Communication devices require elaborate networking to enable long distance communications. Computers have built-in LAN (local area network) to enable long distance communication. Long distance phone calls are made possible by digitally modulated analog carrier signals.