Which term describes a network used for integrated telecommunications?

The term that best describes a network used for integrated telecommunications is Integrated Services Digital Network (ISDN). ISDN is a set of communication standards that allows the simultaneous transmission of voice, video, and data over the traditional circuit-switched telephone network. This technology integrates various types of services, making it versatile for different communication needs.

With ISDN, users benefit from higher data transfer rates and a more reliable connection compared to analog systems. It effectively combines various telecommunications services, providing an efficient way to manage voice and data traffic. This is why the term Integrated Services Digital Network is the correct answer—it accurately reflects the purpose and capabilities of such a network in facilitating integrated communication services.

The other options do not accurately represent established telecommunications networks. For instance, the term "International Services Digital Network" does not correspond to any widely recognized standard. Similarly, "Information Services Digital Network" and "Integrated System Digital Network" are not valid terms in the context of telecommunications infrastructure.