What is purpose of end hinges that is mounted on 4 section garage doors? This one is from a Pella garage door and mounts on side above where the rollers are mounted. The door uses 6 of these. -3 on each side of the door.
They connect the sections together so the entire door moves when opening or closing it.
3 on each side means each except the bottom one is connected to the one below.
Clearly, Pella likes to do things the hard way. Normally that whole assembly is one standard part: the hinge and the roller holder all in one piece.
What Pella's setup does, however, is allow the hinge pivot point to be inside the door. That is why you see a chamfer/relief on the top edge of the door section, to keep the door segments from pinching.
The standard part has the hinge point about 3/8" this side "above" the door's interior surface.
The other hole is for the roller, note that each row of hinges puts the roller farther away from the door, since the roller track is at a slight slant.