A piano has heavier weighted keys which requires stronger muscles to play.
Non piano keyboards (while some have weighted keys) often generally have plastic unweighted keys which don’t require so much muscle strength.
Inevitably it’s a little more complicated that that. Depending on what you are trying to achieve it may not even matter.
You can often transition from piano to keyboards but moving from keyboards to piano is usually a little harder. Whilst there can be a crossover they are often treated separately
But they all have the same black and white keys!
Yes they do but they feel different and the subtleties of technique can be important. It’s a bit like saying how to drive a car, articulated lorry or bus. They all use the same basic accelerator, brake and clutch but they all feel different.
If you have any doubts you are welcome to try at your introductory lesson.
Play my pro-level plastic keyboards then play my Yamaha grand piano – then you’ll see what I mean.
If you wanna play keyboards and not worry about piano then that’s fine. There a plenty of famous keyboard players who don’t or can’t play piano (Nick Rhodes of Duran Duran, Martin Gore of Depeche Mode, Brian Eno come to mind)
So if you wan to play keyboards and not bother about piano that’s fine. It’s very doable. Many of the skills are transferable but you should understand the difference when you start out
And remember at any point in time you can switch to either or both without too much trouble
It’s your decision and your musical journey.
