An unmanaged Postgres database on Hatchbox is the full Postgres experience, installed locally on your server. You can install as many instances as you want for free, but you will be limited by the space on your server. The reason it is called "unmanaged" is to draw attention to the fact that you are responsible for backing up your database and there are no fancy features like replication or the ability to scale up. (You can upgrade your server for more space though)
Hatchbox unmanaged databases reside on the same network as your other servers so no SSL setup is required. You can keep your unmanaged databases up to date with security and bug fixes with the Hatchbox configuration which is a simple one click process.
Basic automated backups are also available for unmanaged Hatchbox databases.
Unmanaged databases are perfect for students, hobbyists, side projects or small startups just getting started.
A managed database can provide peace of mind for production databases as they can provide replication, automated and up to the minute backups among other niceties. These managed databases will cost extra and the prices vary, and are set by your server provider.
It is strongly recommended to use a managed database for any important apps you may have where you cannot afford to lose any data or where any downtime due to database problems may cause a loss of revenue.
(Feedback is welcomed, good or bad. Please open a ticket if you see any problems or errors and thanks for reading.)