H SQL and other DBs

Hi guys, I'm trying to understand what is the role of the H SQL DB in Mendix apps. Do all apps use HSQL to store data? Or can I use other popular DBs? Using a popular DB, is data stored directly in that DB or will the data be stored in HSQL and eventually synchronized with the "real" DB? Thanks
1 answers

HSQLDB is just another database that you can select as your data database. You can also select PostgreSQL, SQL Server and Oracle. Data is directly stored in those as well without additional steps.