The major differences are regarding what type of hardware you have access to. A private cloud has all the benefits of a public cloud with none of the drawbacks. You still get scalable, on-demand computing resources, but without having to share them. There is no chance that your cloud services will be interrupted by outside factors.
Private cloud is not the same type of cloud that public clouds are. It is an IaaS where there is no virtualization layer like VMware or KVM. All hardware resources (CPU, RAM, disk space, bandwidth) are dedicated to your use only. This means you don’t share the resources with any other users. This makes private cloud your best option if you have high resource utilization requirements, need direct access to hardware, or have highly sensitive data that you don’t want to share with anyone else.
Public cloud hosting, on the other hand, is exactly as it sounds; you share hardware resources with other users. So as capacity requirements increase and decrease, so does the cost to you as a customer – these types of hosting services are known as utility computing. Virtual Private Server (VPS) is virtualization technology that creates a dedicated slice of a physical server for your account. That means you aren’t sharing the same physical hardware with anyone else, but still get some of the benefits and reliability of shared hosting at a fraction of the cost. You manage your VPS through the command line or via an included control panel like cPanel or Plesk, and can resize your VPS instance almost instantly on-demand.