Low resolution photos being removed from mac

I’ve recently got a new iPad and want to get rid of my MacBook Air.

for context, my MacBook Air, new iPad and iPhone are all on the same Apple ID.

i want to clear my MacBook completely, however its telling me ‘x amount photos and videos will be removed from this mac - full resolution versions will remain in iCloud’

if i continue with this, does this delete them from my other devices too?

it’s over 29,000, so im very worried i might mess this up!

Thank you