We now have the basic understanding of What Cloud is? Let’s try to get some knowledge on different types of Cloud and clear some misunderstandings as well.
We often think or heard that Virtualization is the base of Cloud, However it is a myth or a half told truth. Cloud can be provided for Physical infrastructure as well. For example Oracle Cloud Infrastructure (OCI) formerly termed as Oracle Bare Metal Cloud Services (OBMCS). On the contrary all Virtual or Physical Datacenters can’t be considered as Cloud.
How do we classify a Datacenter as Cloud…The simplest and logical answer is …it should meet some criterion as below:
(a) It should have a high level of orchestration or Automation. Almost 100% of the operations/tasks should be automated.
(b) It should provide a self service feature i.e. people can order and use the resources with no or minimal restrictions.
Note: You may have some internal approval processes out of the box within your organization.
(c) It should have deep and complete monitoring and alerting features in built.
(d) It should have proper backup and recovery features in built.
(e) Another important aspect is, it should have appropriate security, user identity management and logging feature.
Typically we have two types of Cloud, They are Private Cloud and Public Cloud classified based on the accessibility i.e. who is the end user of the Cloud resources/services.
To understand this, Suppose We have a fully automated Datacenter which meet all the above requirements and that we have built up for various purposes of company like Running company Applications, Hosting company Websites, Running email system etc.
Till the time all of these resources/services are accessed and utilized by people of the same company or its subsidiaries it is termed as Private Cloud. The Access and Utilization are strictly prohibited to as mentioned and no external companies or people can use them.
Two or more similar Datacenters separated apart but connected to each other via any means are still collectively termed as Private Cloud with restricted accessibility. Private Cloud can provide services to within a State, Region, Country or spread across borders.
On the other hand the moment you make the resources/services accessible to other company(s) and external people it is termed as Public Cloud.
Similar to Private Cloud, Public Cloud can also provide services to within a State, Region, Country or spread across borders with no restriction on who is using the resources/services.
In simple words Private Cloud and its resources/services can/must only be accessed and utilized by the company or its subsidiaries. However on the contrary Public Cloud and its resources/services can be a accessed and utilized by anyone who is willing to use it.