Before computers, a popular way to store data was on index cards. If you ran a gardening supply store, you could keep track of your products by creating a card for each product, dividing the cards into product categories, and then alphabetizing the cards in each section by product name. Each card would contain relevant data such as the product’s name, unique identifier, category, price, description, and the supplier’s name and phone number.

To find all of the products from a specific supplier, you either needed to keep track of the products on a separate sheet of paper or go through the cards and pull every one representing a product made by that supplier.

If you store the same data on the computer, however, you can find all of the products from a specific supplier much more easily. As an example, you might create a Microsoft Word table with a column for each type of data you want to store.

With the list in a Word table, you can change the order of the table rows to group all of the products from one supplier together...all you need to do then is scroll down through the table until you find the products from the supplier you want.

Using Word to store your data isn’t the best solution, however. One limitation is that there’s no way to combine information from two tables, so you need to write the supplier’s phone number in every row representing a product from that supplier. If that phone number changes, you need to change the phone number entry in every table row representing a product from that supplier.

Databases, by contrast, are designed to combine data from several sources into a single table. After data is entered into a table, it can be combined with other tables in the database to produce valuable information. It’s possible, for example, to store information about suppliers in one table and information about purchase orders in another table. If a supplier changes its phone number, you need to change the phone number only once.