If you’ve ever added a new product to Magento, you know that you’ve had to add some title, description and price to it (there are more attributes but we are using 3 for this example). When you saved your product, you used a total of 3 tables to save that information (a few more, but those are irrelevant for our example). First, a new Entity was added to DB, second, In Attribute table, you saved attributes (title, description and price) attached to that product, and finally to Value table, you saved 3 rows, attached to that product’s attributes.