The Oracle Autonomous Database (ADB) is Oracle's current flagship database product and rightly so! Each instance comes with self-tuning, self-patching and several Oracle Database Options that customer would otherwise have to purchase separate licenses for. Database developers will also be pleased to know that there are a suite of tools at your disposal including Oracle Application Express (APEX), Oracle REST Data Services (ORDS) and Oracle Machine Learning Notebooks.
The minimum instance you can create will have 1 CPU and 1 TB of storage and with so much features, doesn't come cheap. Here's the good news though, Oracle provides everyone two Always Free ADBs through the Oracle Cloud Free Tier offering. Yes, that's a great deal for anyone wanting to host a simple web application on the Internet. It is however, not without limits.