The admin database stores your API definitions (resources, logic, security, filters, and Data Explorer settings) in the admin database (meta repository). This database is transparent for cloud/appliance users.

You can connect to multiple databases, so these options are not restrictive. For example, you can click New empty Database and then connect your API to multiple databases. Your database can be in the cloud or on-premises. API Server requires access to your database, whether it be stored in the cloud or within your firewall. Using this procedure allows you to connect to your on-premises databases.

When you create your API and connect to your database, API Creator reads your database schema. After that, the API Creator references the database objects and determines the names (table names, column names, and foreign key names) from the database catalog. Finally, the API Creator uses the database schema to create resources and the JavaScript object model, that you can easily reference in your application.