Yeah the USSR had train tracks of a slightly different gauge as the tracks in Germany, wider if I am not mistaken. Lots of their Nazi equipment was shipped by the rails after the Wehrmacht engineers had refitted the tracks. For example: Tanks usually have a pretty short length of time you can reliably drive them before needing maintenance, which in the case of the overengineered German tanks, could sometimes mean an entire engine rebuild. It was simply practical to ship the tanks by rail until they were close to the front at which point they could be unloaded and driven the remaining distance.

If you look up a lot of the early objectives of Operation Barbarossa they were often rail hubs. Not only were these important to capture for Nazi war ambitions - they also wanted to deprive the Soviets of key infrastructure that could be used to efficiently resupply the Red Army. The Red Army had a lot of trucks provided through Lend-Lease but aside from the rails they also used a lot of animal-driven wagons given the necessities of warfare. Better to ship supplies on the back of a mule than nothing at all when the roads turned to mud in the spring rain. The history of the logistics on the Eastern Front is mind boggling.