CRUD is an acronym that stands for: Create, Read, Update and Delete. CRUD Permissions are permissions that you give to a group of users to Create, Read, Update or Delete content from a dataset. If a group of users does have access to a Create permissions on
Dataset A. Then it means that they can create new records in that
Dataset A. If that same group of users doesn't have the Delete permissions on that same
Dataset A, then it means they won't be able to delete records in that dataset (not even the ones they created).
In OSF, the CRUD permissions are attached to the datasets. You won't have CRUD permissions on individual records, but only on datasets.