1. There is no company called "iPhone".
The legal name of the company is Apple Inc. It has the authority to update system software on iPhone and iPad brand devices. When people refer to "iPhone", they refer to the division of Apple responsible for iOS updates.
Just like there is no company called "Android".
A company called Google Inc. acquired a company called Android Inc. But there is no one entity with authority to update system software on devices. This is delegated to device manufacturers (for Wi-Fi-only tablets) or to carriers (for phones and tablets supporting cellular data service).