What does the term "training" refer to in this context?

In the context of metropolitan transportation, "training" refers to a grouping of multiple-unit cars that are coupled together to operate as a single train. This configuration allows for coordinated control, where one operator can manage multiple cars simultaneously, enhancing efficiency in transportation operations.

This concept is essential for effectively managing passenger flow and ensuring that multiple train units can work seamlessly together, increasing the overall capacity and responsiveness of the transit system. By coupling several units into a training formation, rail systems can optimize service, especially during peak times, as more passengers can be accommodated efficiently.