When I was a kid, I had an Instamatic camera. It used a 'fixed focus' lens -- which meant essentially that it didn't focus at all. In bright light and daylight, you got a pretty good snapshot. But in dimmer light... Well, it didn't really work in dimmer light. But, aside from the shutter and the thumb-driven film drive, the camera had no moving parts.
When I take pictures with my phone, on the other hand, it really does seem to be focusing.
Does anyone know, do phone cameras actually have little mechanical lenses moving back and forth to focus?