Describe the delete set-to-null option (for implementing a referential integrity constraint)

What will be an ideal response?

The delete set-to-null option allows a record to be deleted if its primary key value is referred to by a foreign key value of a record in another relation. As a consequence, in all of the records where the foreign key value refers to the primary key of the record that is being deleted, the value of the foreign key is set to null.