How is information exchanged between tables in a relational database?

Information exchange between tables in a relational database is carried out using foreign keys and JOIN operations.

• Foreign key — is a field in one table that references the primary key of another table, ensuring a link between records.
• JOIN — is an SQL operation that combines rows from two or more tables based on a related field.

Example of an SQL query with JOIN:

SELECT orders.id, customers.name
FROM orders
JOIN customers ON orders.customer_id = customers.id;

Here, the orders table is linked to the customers table through the customer_id field, allowing you to get order information along with customer data.