Why am I using an inner join?

An inner join returns only the rows that have matching values in both tables. It is used when you need to combine related data from two tables and you only care about records that exist in both. For example, if you have a Customers table and an Orders table, an inner join on CustomerID will give you all orders along with the customer details, but only for customers who have placed orders. It filters out customers with no orders and orders with no matching customer, ensuring data consistency. Inner joins are efficient because the database can use indexes on the join columns, and they are the most common type of join for relational queries where relationships are mandatory.