Your garage door has two sensors—one on each side of the track, near the floor. They shoot an invisible beam of light at each other.
If that beam gets broken (by a kid, a bike, or a pile of laundry you swore you’d put away), the door stops closing. Safety first, right? The orange light means one sensor isn’t seeing the other’s beam.
It’s basically your door saying, “I’m not closing until you fix this, pal.” Smart, but annoying.