What happens when you remove an account on mobile device?

I recently moved my NC setup from the Raspberry to a a proper server. All went fine but during the process there were a thing I want to check first with you:

As I now have two accounts (the old and new NC) on my phone I would like to delete the old account. if I click remove it states that ALL local data gets removed. What does that mean? Is this only NC app related stuff or is it also removeing synced files etc?

Thanks for helping!

as far as i remember:
the NC App will not leave anything from your NC Data on the local device. All your staff will only be on the nextcloud, the account was connected to.