There's no doubt that cloud computing is one of the most significant technology shifts that has ever hit the IT market. However, if there's any one word that characterizes cloud computing, that word is confusing. It seems that every vendor has a different definition of what cloud computing means. And then when you throw in the public cloud, the private cloud solutions, and the hybrid cloud, it's no wonder so many people are confused. In this column, I'll try to dispel some of that confusion as I answer 10 of the most common questions about building the private cloud by using Microsoft System Center Virtual Machine Manager (VMM) 2012.

Related: Easing into the Cloud with HP Virtual System for Microsoft

1. How is the private cloud different from the public cloud?
Cloud computing in general has come to be identified by its four main attributes: pooled resources, elasticity, self-service, and usage-based metering. These attributes are found in both the public and the private cloud. In simplified terms, the public cloud includes resources that you lease from a cloud hosting provider and the private cloud consists of your on-premises computing resources.

2. Isn't cloud computing, and especially the private cloud, really just the same as virtualization?
The private cloud is more than virtualization. Virtualization lays the foundation for the cloud by abstracting the server and workload from the underlying hardware. However, the private cloud adds a number of other features, such as service-based management, the ability to automate operations, self-service end-user capabilities, and usage-based chargeback, that go beyond plain virtualization.

3. How do you build the private cloud for Windows Server and its applications?
To build a private cloud using the Microsoft stack, you need to use VMM 2012. VMM 2012 goes way beyond the virtual machine (VM) management functions that were provided by VMM 2008 or VMM 2008 R2, and it introduces a new management layer that enables the creation of private clouds.

4. What makes up a private cloud built with VMM 2012?
Although VMM 2012 still lets you manage VMs, it also includes several new management constructs that let you create a private cloud layer on top of your on-premises resources. In VMM 2012, the private cloud is made up of computing resources called a Fabric and collections of related VMs and other resources known as Services. Users are given access to the private cloud through Active Directory (AD).

5. Is a service the same thing as a VM?
No. In VMM 2012, a service is a higher-level concept than a VM. A service might contain multiple VMs. For instance, you might create a service out of a multi-tier application where one VM contains the front-end web server, another VM contains the application server and business logic, and another VM contains the back-end database; the service would also include the virtual network definitions. The service lets you manage all of these entities as a single unit.

6. What is the Fabric?
In VMM 2012, the Fabric essentially represents your local computing resources. This includes your VMs, your virtual networks, and any Storage Management Initiative Specification (SMI-S) compatible storage. Services are built by using the computing resources that comprise the Fabric.

7. Can a VMM 2012 private cloud use other virtualization platforms besides Hyper-V?
Yes. In addition to managing Hyper-V servers, VMM 2012 can be used to manage VMware vSphere and Citrix XenServer. In order to manage vSphere servers, you must have the VMware vCenter Server management product installed.

8. So what gives the private cloud self-service capabilities?
The main feature that provides VMM 2012 with self-service capabilities is the VMM Self-Service Portal. The VMM Self-Service Portal is a web application that lets authorized end users manage their own VMs according to the policies and quotas that have been assigned to them.

9. When is VMM 2012 due to be released?
System Center Virtual Machine Manager 2012 Release Candidate is now available. The final version should be available in the first half of 2012.

10. Is VMM 2012 the only product that can build the private cloud?
No. VMM 2012 is Microsoft's answer to building the private cloud, but there are other private cloud solutions available. One of the most notable is VMware's vCloud Director.

Related: Microsoft and the Private Cloud and Top 10 New Features in Virtual Machine Manager 2012.