Once the circuit switches have established a connection, that connection is maintained on a temporary, continuous, and exclusive basis. The connection is continuous, as it is continuously available in support of transmission in both directions, whether or not any real information is being transmitted. In other words, silence bytes are considered just as important as sound bytes. The connection, or path, is exclusive, as it is shared with no other transmissions. That is not to say that other conversations are not traveling the same physical path, but it is to say that no other conversations share the same logical channels over the same physical circuits, or paths.
Circuit switches offer outstanding performance.
In fact, they offer virtually perfect performance. But, they are highly inefficient for anything other than realtime, uncompressed voice or video. This packet technology was developed specifically in support of interactive data communications between asynchronous host computers and terminals. The application was what we then called time-sharing, which involved dumb remote terminals sharing access to files and applications residing on very expensive centralized mainframe host computers. Packet switches act to switch data in discrete units known as packets, or datagrams, each of which is of a fixed minimum and maximum size.