People use databases to keep information stored so they can access it from different locations and devices.

-Analytic- read-only system that stores historical data on business metrics such as sales performance
-management- contains all relevant information about the components of the information system used in an organization's IT services and the relationships between those components
-operational- used to manage dynamic data in real-time. These types of databases allow you to do more than simply view archived data. Operational databases allow you to modify that data (add, change or delete data), doing it in real-time.
-flat file- describes any of various means to encode a database model (most commonly a table) as a single file

SOURCES- Wikipedia

In the diesel field, a parts department might use a database to keep track of parts in inventory and sold. A service manager might use a database to keep track of different projects in the shop and what has been paid for.