The rapid development of several different kinds of terminals and the greater ease that they offer for the use of real-time on-line systems are having a major impact on the computer industry and on computer applications. Trends that influence the increasing utilization of terminals are identified. The major subsets of the terminal market include keyboard/printer terminals, CRT terminals, "smart" terminals, remote-batch terminals, real-time data acquisition and control terminals, transaction and point-of-sale terminals, and several miscellaneous types of less frequently used terminals. Applications, characteristics, and some design considerations are discussed for each of these types of terminals. The important relationship between terminal capability and communications requirements is analyzed. To the extent that stored program capability in the terminal permits part of the task to be performed locally, communication of data between terminal and central communication can be reduced with a consequent reduction in communication costs and increase in overall system reliability.