An alpine standard (DIN) sole is the traditional flat, hard plastic sole found on classic ski boots. It's designed purely for skiing—no rocker shape or rubber traction, just rigid plastic that clicks securely into any standard alpine binding.
The biggest advantage of DIN soles is universal compatibility. If you have older bindings or standard alpine bindings without the GripWalk (GW) symbol, DIN-sole boots will work safely with no hassle. You skip the compatibility worries entirely.
The trade-off is walking comfort. DIN soles are notoriously slippery on ice, hardpack, and smooth surfaces like lodge floors or parking lots. If you've ever felt like you're ice skating to the lift in your boots, that's the DIN sole at work.
DIN soles still make sense if you're a dedicated resort skier with standard bindings and don't want to replace them. But if you're buying new boots and your bindings are GripWalk-compatible, the newer rubber soles offer far better off-snow comfort without sacrificing skiing performance.