Pencils

The first and second generation Pencil use an entirely different pairing and charging interface. The second generation Pencil can only be used with iPad models that have the magnetic/inductive dock that is exclusively designed for the second generation Pencil.

The first generation Apple Pencil, compatible with other models of iPad, uses the physical Lightning port for both pairing and charging the first generation Pencil. This pencil can only be used with compatible iPad models that have a Lightning connector.

In summary, the Apple Pencil models are not interchangeable - and can only be used with the iPad that has appropriate internal hardware.

Connect Apple Pencil with your iPad - Apple Support

Apple Pencil compatibility - Apple Support

The Logitech Crayon is a much simpler stylus than either of the Apple Pencil models. Whilst Crayon interacts with the screen of compatible models of iPad, and uses a standard Lightning cable for charging from a standard USB Power Adapter, it doesn’t use Lightning for Bluetooth pairing or charging from iPad - and neither can it use inductive charging.

The Crayon and two different models of Apple Pencil are all technically quite different - but achieve similar functions.

The iPad Air 4 uses similar screen technologies to the Pro models, making it compatible with the 2nd generation Apple Pencil. The first generation Pencil will not work.

I hope the information and insight proves to be helpful - if only in comprehending the more significant differences between them.

It might be worth adding a minor corollary to my earlier notes. The Logitech Pencil was developed by Logitech in partnership with Apple. The Crayon is principally aimed at educational environments. The Crayon and two models of Pencil are based upon the same Apple-proprietary stylus/screen interface technology.