Oracle PaaS automates the underlying components typically associated with installing, integrating, managing, and maintaining Oracle software and hardware.
You may want to start with our FAQ page about OCI. Most companies adopt OCI as a lift and shift strategy to get out of the data center business. In turn, Oracle allows customers to apply traditionally-licensed software to OCI services via a 2:1 OCPU:Processor conversion akin to core factors. This model is called bring your own licensing, a.k.a., BYOL.