# Oracle Cloud 1. [Concepts](#concepts) 1. [Compartments](#compartments) 2. [Further readings](#further-readings) 3. [Sources](#sources) ## Concepts ### Compartments Compartments are tenancy-wide and extend across regions. They can also be nested to create hierarchies up to 6 levels deep. After creating a compartment, you need to write at least one policy for it; until then, no one can access it except administrators or users who have permissions set at the tenancy level. When creating sub-compartments, they inherit access permissions from compartments higher up their hierarchy. Before deleting a compartment, all its resources must have been moved, deleted or terminated, including any policies attached to the compartment itself. ## Further readings - [oci-cli] - [compute images] ## Sources - [Required keys and OCIDs] [compute images]: https://docs.oracle.com/en-us/iaas/images/ [required keys and ocids]: https://docs.oracle.com/en-us/iaas/Content/API/Concepts/apisigningkey.htm [oci-cli]: ./oci-cli.md