Can you explain how the INNER JOIN operator works in SQL?

The INNER JOIN operator in SQL is used to combine rows from two tables based on a matching condition of values in specified columns. It returns only those records for which a match is found in both tables.

For example, if there is a orders table with orders and a customers table with customers, then an INNER JOIN on the customer_id field will return only those orders that are associated with existing customers.

Example:

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

The result will be rows with orders and customer names for those orders.