Yes, they are no longer the same. What are the differences? Josh Centers in TidBITS:
Apple markets iPadOS as being a completely different operating system than iOS, it’s essentially iOS 13.1 with a few iPad-specific features.
Fair enough. Differences? Many. A few:
iPadOS improves the multitasking system, beefs up Safari to support complex Web apps, adapts the Home screen for the larger iPad screens, improves markup features, and adds a new one-handed floating keyboard.
Good list if you sweat the details. iPadOS moves iPad closer to the Mac in capabilities.