A database and all the additional information required for its operation are collectively known as a database instance. Each database instance has a database name and consists of volumes, all the files in the run directory, and a collection of metadata (including configuration data, database parameters, and volume paths).
You can create database instances with the Installation Manager or the Database Manager database tool.
See also:
Concepts of the Database System, Overview of the Database System
Database Manager GUI, Creating a Database Instance
Database Manager CLI, db_create