Since the first development of the modern electronic digital computers in the 1940s, computerization has infiltrated almost every area of society in nations with advanced technology. Computers are available in many formats for use in industries, schools, and individual homes, and computer networks and auxiliary devices provide a means for the rapid transmission of a wide range of data. The laser is also of great potential importance for the future of communications. Modulated beams of the coherent light produced by lasers can transmit a much larger number of messages at a time than can ordinary telephone systems. Prototype laser communications networks are already in operation, and they may eventually replace to a large degree the use of radio waves in telephony.
Laser beams are also ideal for use in space for satellite communications systems.
Records and tape recorders are used extensively in the teaching of languages. Motion pictures on various subjects are part of classroom instruction. Closed-circuit television instruction is growing rapidly, enabling a teacher to instruct students in many classrooms. By means of videotape, a single lesson can be presented many times. The instruction provided by teaching machines is specialized and often programmed to serve the student's individual rate of progress, thus permitting interaction between the student and the machine.