Why are blank and null distinct options for a django model?

Question

When defining fields in a django model, there are two ways to say that the field is allowed to be empty. null means it can be empty in the database, and

Answer 1

null=False, blank=True is common for CharFields, where a blank answer is stored in the db as a blank string rather than a null. The other way around doesn't make much sense to use.

For non-string fields, a non-answer is stored as a null, and so you need both.