Albert Einstein maintained that all motions are relative with the
exception of light. But the train station does not begin to move
through space toward the train. NO there is an absolute distinction
that can be made to show what is really moving and what is not.

The train accelerated. You might say "so did the station" But only the
train felt THE WEIGHT of acceleration. That is how we tell the
difference in the Twin Paradox. Only the frame that experienced the
weight of acceleration will be moving through space. Therefor only the
trains clock goes slower.

New motion is only created by acceleration and acceleration is always
detectable.

Mitch Raemsch; Twice Nobel Laureate 2008