It ensures that you cannot change or delete the primary key value in the primary table that is used in a relationship with another table.

It ensures that all the related records will be deleted automatically when the related record in the parent table is deleted.

It repeats the recent delete operation to all the records of current table.

It causes all the records of all tables in a database to be deleted.

It changes the foreign key value of all related records when the primary key value in the parent table is deleted.