Hey all!

Hope you are OK!

In the last post: Oracle Cloud Infrastructure – Post 1 – Creating an OCI Account, we created our Cloud Account.

In this post, we will explain some key concepts of Oracle Cloud Infrastructure.

First of all, when you created your account you chose a region, in our example it was Ashburn.

If you want, you can subscribe for more than one region.

So, in the first page click on the Globe button in the right top corner. The page below it will appear. So, if you want to subscribe to more regions, just click on [Subscribe To This Region] in the region that you want to subscribe it.

Well, let’s understand some key-concepts.


Compartment is a collection of related resources (instances, VCNs, block volumes, etc). Can be accessed by groups that have have been given permission by an administrator. When you sign up for OCI, Oracle creates  your tenancy, which is the root compartment. The best practice is to never use root compartment to create your resources. You can create compartments to organize and isolate your cloud resources, for example:



Region is a localized geographic area. So, to consider a DR environment, you should create your resources in more than one region.


Availability Domain

Availability Domain is one or more data center located within a region isolated from each other. So, if you want to implement a HA environment, you can create your resources in more than one availability domain in same region.

So, in this case, the state-of-the-art is to create your resources in a region in more than one Availability Domain to guarantee a high available environment. Then, create a DR environment in another region (in more than one AD in the second region).


Virtual Cloud Network

VCN is a virtual version of a traditional network, with subnets, route tables, security lists (firewall) and gateways.



Instance is usually the term as we identify a Compute host (VM/Bare Metal).



Shape specifies the number of CPUs and amount of memory.


Block Volume

Block Volume is a virtual disk.


Object Storage

Object Storage is a storage architecture to store and manage data objects (files). Object Storage works as a bucket.


Oracle Cloud Identifier (OCID)

OCID is an Oracle-assigned unique ID for each resource in OCI.


You can read more about OCI Key Concepts here: https://docs.cloud.oracle.com/iaas/Content/GSG/Concepts/concepts.htm