What's the Difference Between Cloud and Virtualization?
By Tobias Geisler Mesevage
If you think of cloud computing and virtualization as being interchangeable, you are not alone. You aren’t correct, but you are certainly not alone.
Forrester Research found that 70% of what IT administrators call “private clouds” don’t actually fit the definition of cloud computing.
The confusion is understandable when you break down each term and learn that the cloud has more in common with virtualization technology than it does differences.
In this article, we break down the basics of cloud computing and virtualization technology and the benefits of each.
What Is Cloud Computing?
The National Institute of Standards defines cloud computing as “enabling ubiquitous, convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications, and services).”
To be a cloud, NIST has determined it must have the following five essential characteristics:
- On-demand self-service: A consumer can unilaterally provision computing capabilities, such as server time and network storage
- Broad network access: Capabilities are available over the network through multiple clients and devices
- Resource pooling: The provider’s computing resources are pooled to serve numerous consumers using a multi-tenant model
- Rapid elasticity: Users can add or reduce capacity through software
- Measured service: Automatic control and optimization of resources detailing who is using what and how much
Without those five essential characteristics, it is technically not a cloud.
The cloud model is comprised of three service models:
- Software as a Service (SaaS): The consumer can use the provider’s applications running on a cloud infrastructure
- Platform as a Service (PaaS): The consumer can deploy on the cloud infrastructure, applications created using programming languages, libraries, services or tools supported by the provider
- Infrastructure as a Service (IaaS): The consumer can provision processing, storage, networks, and other computer resources to deploy and run arbitrary software
There are four deployment models of the cloud:
- Private Cloud: The cloud infrastructure is provisioned for exclusive use by a single organization comprising multiple consumers.
- Community Cloud: The cloud infrastructure is provisioned for exclusive use by a specific community of consumers from organizations that have shared concerns (e.g., mission, security requirements, policy, and compliance considerations).
- Public Cloud: The cloud infrastructure is provisioned for open use by the general public. It may be owned, managed, and operated by a business, academic, or government organization.
- Hybrid Cloud: The cloud infrastructure is a composition of two or more distinct cloud infrastructures (private, community, or public).
What Is Virtualization?
Contrary to what some believe, virtualization is not cloud computing. It is, however, a fundamental technology that makes cloud computing work. While cloud computing and virtualization rely on similar models and principles, they are intrinsically different.
Simply put, virtualization can make one resource act like many, while cloud computing lets different users access a single pool of resources.
With virtualization, a single physical server can become multiple virtual machines, which are essentially isolated pieces of hardware with plenty of processing, memory, storage, and network capacity.
Each virtual machine can run independently while sharing the resources of a single host machine because they’ve been loaded into hypervisors. Hypervisors, also known as the abstraction layer, are used to separate physical resources from their virtual environments. Once resources are pooled together, they can be divided across many virtual environments as needed.
Cloud Computing vs. Virtualization
Deciding which to implement for your business depends on the type of business and the requirements you have.
For smaller companies, cloud computing is easier and more cost-effective to implement. Resources are accessed via the Internet rather than added to the network.
Many small businesses are turning to the cloud for applications such as customer relationship management (CRM), hosted voice over IP (VoIP) or off-site storage. The cost of using the cloud is much lower than implementing virtualization. Cloud computing also offers easier installation of applications and hardware, access to software they couldn’t otherwise afford, and the ability to try software before they buy it. It requires a small investment to implement a cloud-based application.
For some businesses, virtualization is the smarter choice and can save money in several different ways:
- Adding many guests to one house maximizes resources, which means the business needs fewer servers. This cuts down on operational costs.
- Fewer servers mean fewer people to look after and manage servers. This helps to consolidate management, thereby reducing costs.
- Virtualization also adds another layer of protection for business continuity, since virtual machines will limit the damage to itself.