In this lesson, we will learn how to use transactions to ensure data integrity. Transactions let us group multiple operations together and ensure that they all succeed or fail together. For example, if we might develop a system where changing the price or some other data in a product removes the reviews for that product. Or at least a toggle to allow that option on change in the user interface. We may need this when we've changed a product so much that the reviews are no longer relevant. So we have two operations that need to happen together. We need to update the product and delete the reviews. If either of these operations fails, we want to roll back the other operation. For example- if the product update fails, we don't want to delete the reviews. If the review deletion fails, we don't want to update the product. We can use a transaction to ensure that both operations succeed or fail together. If either operation fails, the transaction will be rolled back and the database will be left in the state it was in before the transaction started.