The one-way videoconference allows an organization to present video information to large audiences in multiple locations at the same time. However, since both types of videoconferencing take place in real time, live, the audience can participate over the phone. Each carries its own set of system requirements and each accomplishes quite different tasks. Full-motion videoconferencing is like watching television. You can see facial expressions, hand gestures, and general body language.
Motion video is used primarily for images of people.
There is far more information in moving pictures then in a still image. Consequently, the size of the communications channel required to transmit and receive motion is far greater than that required for a still image. Most systems therefore, incorporate digital compression techniques to reduce the bandwidth required for motion videoconferences. This bandwidth is beyond the capacity of the standard telephone cable. The resulting signal can be transmitted over less than full bandwidth channels.