What defines simulators in the context of training devices?

Simulators in the context of training devices are defined as tools that replicate all or most system functions. This means that simulators are designed to closely mimic the operational environment and the capabilities of actual systems, providing a realistic training experience. By effectively replicating system functions, they allow soldiers to engage in training scenarios that are as close to real-life situations as possible without the risks associated with actual operations. This realism helps in enhancing the learning aspect by allowing trainees to practice skills, decision-making, and problem-solving in a controlled setting.

The other options do not fully capture the essence of what a simulator is. While teamwork enhancement, physical tools for combat simulation, and advanced training aspects may be features or benefits of some training devices, they do not specifically define simulators. The primary characteristic that distinguishes simulators is their ability to closely emulate system functions and enable comprehensive training experiences.