How do you represent referential intergrity in a relational model?

Referential integrity in a relational model is represented through the use of foreign keys. A foreign key in a table points to a primary key in another table, establishing a relationship between the two tables. This ensures that any value entered in the foreign key column must correspond to an existing value in the referenced primary key column, thereby maintaining data consistency and preventing orphaned records. Additionally, constraints can be applied to enforce actions like cascading updates or deletes when the referenced data changes.