What does the term 'dual fiber' indicate in fiber optic technology?

The term 'dual fiber' refers to a fiber optic cable that contains two fibers, which facilitates bi-directional communication. This setup allows data to be transmitted and received simultaneously over separate fibers, improving communication efficiency and performance. Each fiber can handle signals in opposite directions, which is particularly beneficial in applications where continuous communication flow is necessary, such as in telecom networks or data centers.

In contrast, the other choices focus on different attributes that do not align with the dual fiber concept. For instance, a single fiber for one-way communication would imply a different configuration, whereas the specification of long-distance signals applies to various types of fiber optics without directly speaking to the dual nature of the fibers. Similarly, multi-mode fiber pertains to a specific classification of fiber concerning bandwidth and signal propagation, rather than indicating the number of fibers present in a cable.