Difference between django's OneToOneField and django's OneToOneRel

Question

What's the main difference between django's OneToOneField and django's OneToOneRel.

When I searched I came across:

What's the difference between django OneToOneField and ForeignKey?

Answer 1

OneToOneRel is an internal class which implements the back reference of a one to one relationship. It is not documented anywhere, not part of any public api, and is not for use in your app.