How does the concept of SR units relate to relativity theory?

The concept of SR units, or spacetime units, is a fundamental aspect of special relativity theory. In special relativity, space and time are combined into a single four-dimensional spacetime continuum. SR units help measure distances and intervals in this spacetime, accounting for the effects of time dilation and length contraction at high speeds. This concept is crucial for understanding how objects and events are perceived differently depending on their relative motion, as predicted by special relativity theory.