I have a question on this site permission/access level thing. This is my requirement. All users of the overall site get permission to view, edit and delete files and folders. Yet there is one folder/file which is so crucial where the permissions should be still in place except the deletion permission. How can that be achieved actually? The thing is, as far as I understood, the overall site permission level will be inherited for the folder in question as well, right? How can I then differentiate between overall site permissions and specific folder permission. thanks for your tips! kind regards
The concept is known as breaking inheritance. And is far as I know it is considered a bad idea to break the permissions on folders and items. That said Microsoft is doing it big time with the "Share" functionality so... This will work you through the process and in order to prevent users from deleting anything in the protected area I would recommend creating a custom permission set , using contribute as a basis and then remove the delete option.
Yes, as said in other answer, you can do this by breaking inheritance and give unique permissions per folder. Keep in mind Microsoft accepts 50000 unique permissions per list/library. I don't know what Sharepoint version you talking about, but it might you have to deactivate "Limited-access user permission lockdown mode" in site collection features