ORM queries are more readable and relationships more explicit when related_name is specified.

The related_name attribute specifies the name of the reverse relation from the related model back to the model.

Django automatically creates a related_name if related_name is not set. Django uses the lower-case name of the model with the suffix _set.

So in practice, do this

class UniversityStudent(models.Model):
    grades = models.ForeignKey(
      Grade, related_name='students'
    )

for student in Grade.students.all():
  ...

Instead of this

class UniversityStudent(models.Model):
    grades = models.ForeignKey(Grade)

for student in Grade.universitystudent_set.all():
   ...