At first glance, a database may seem a lot like a spreadsheet; it presents data arranged in columns and rows. But that’s where the similarity ends, because a database is much more powerful.

If your database is relational, which most databases are, you cross-reference records in different tables. This means you can create relationships between tables. For example, if you link a Customers table to an Orders table, you can find all the purchase orders from the Orders table that were ever processed by a single customer from the Customers table, or you can refine it further to return only those orders that were processed in a specific time period — or almost any type of combination you can think of.

These table relationships allow a database to support complex queries, using different combinations of columns in tables and filters to precisely control which rows are returned after the query is executed.

A database performs complex aggregation calculations across multiple tables. For example, you might list expenses across a dozen outlets, including all possible subtotals, and then a grand total.