Explain how „parents‟ and „child‟ tables are related in relational database

In a relational database, a "parent" table and a "child" table are related through a common column or key that links the two tables together. This common key is usually a unique identifier in the parent table that is referenced in the child table.

The relationship between the two tables is established through a foreign key constraint in the child table, which references the primary key in the parent table. This ensures data integrity and consistency between the two tables.

When a record is added to the child table, the foreign key value must correspond to an existing primary key value in the parent table. This enforces referential integrity, ensuring that all data in the child table is related to valid data in the parent table.

This relationship allows for data to be organized and managed efficiently in a relational database, enabling the retrieval of related data across multiple tables through join operations. It also helps in maintaining data consistency and preventing data redundancy.