One of my favorite concepts in Oracle Cloud Infrastructure (OCI) is compartments. If you have worked in AWS, at first they may seem redundant and cumbersome, but contrary to that, they are quite useful and make things less cluttered.
I think if AWS would get a chance to reorganize their cloud governance model, they might also introduce something like that but then they don't like to copy thing.
Compartment is used to organize your cloud resources like compute instances, buckets, etc. Compartments are a global concept and they span multiple regions. You can connect your resources across your regions within the same compartment.
The OCI account is called as Tenancy. When you create a tenancy, you also get a default compartment which is called as 'root compartment'. Of course, you can also create many other compartments too.
One of the biggest advantage of OCI compartment is that they enable you to do cost control of your cloud resources. You can assign budgets, quotas, and cost tags to the compartment and its resources. You can attach policies to them and that enable you to control the access in a unified and centralized way. All you have to do is to design the layout of the resources.