Standard passive ventilation uses basic frame cutouts to let air flow naturally through your goggles. It's the most common setup on mid-range models and works by allowing fresh air in while letting warm, moist air escape — no fans or fancy airflow channels involved.
For typical resort days with moderate exertion, standard passive ventilation does the job just fine. If you're cruising groomers, taking lift rides between runs, and not working up a heavy sweat, these goggles should keep your lenses clear without issue.
The limitation shows up when you push harder. Hiking for fresh lines, skiing in wet snow, or running hot can overwhelm standard vents, leading to fogging. If you tend to sweat heavily, wear prescription glasses underneath, or venture into backcountry terrain, you'll likely want enhanced passive or active ventilation instead.