Just about any kind of system might be built around a database.

Your database might contain client information, or stock & invoicing data. There might be a database to store product information. In fact, in the real world a database might easily contain all of these and more, providing a central system around which the business operates.

Specialist database systems might handle room bookings, scan bar codes or automate the emailing of sick and holiday forms around the organization. There really are no limits to the power of databases.