What is a public cloud?

The National Institute of Standards and Technology (NIST) says that you have a public cloud when: “The cloud infrastructure is made available to the general public or a large industry group and is owned by an organization selling cloud services.” Public clouds or “external clouds” are deployments that dynamically provision resources over the internet. These resources, which can be infrastructure, a development platform, or hosted software, are usually fine-grained and self-service. They provide these resources through web applications or web services. These services can be free, like Gmail, or paid, like Vimeo Plus video hosting. Examples include Amazon’s Elastic Compute Cloud (EC2) for cloud infrastructure on demand, Google AppEngine for application deployment to the cloud, and http://Salesforce.com, which offers tools and services to the public on own cloud infrastructure.

There are three other distinct deployment models besides public clouds. They include community clouds, private clouds, and hybrid clouds. Terms such as ‘Cloud’, ‘Private Cloud’, and ‘Public Cloud’ were introduced recently, but they refer to concepts that have been around for more than forty years. The polar opposite of public cloud is a private cloud. A private cloud is available only to one organization and is secured behind the firewall. These are used by organizations that want to keep their data secure and safe inside their own private infrastructure.

A “community cloud” sounds like it would be similar to a public cloud, but they are actually considered by some to be a subset of the private cloud designation. This is because community clouds are still not open to the “public”. Instead, a community cloud is like a private cloud for more than one organization. Google’s “Gov Cloud” is a good example of a community cloud.

A hybrid cloud is just what it sounds like: a mix between a private and public cloud. It includes multiple providers that can be both internal and external. Some computing can be done preformed securely in the private infrastructure while the public facing services can be deployed on the public infrastructure.

About the Cloud
The Cloud uses internet connections to link computing resources together into one big pool of computing resources that the customers don’t need to manage. Cloud computing infrastructure is made up of both remote and local server arrays that share and balance storage or processing power much like an electricity grid shares energy. This allows organizations to provide a much more efficient software deployment architecture or infrastructure service. Organizations can then pass on the savings to their customers through the avoidance of overhead costs (i.e. buying servers) and the as-needed payment model for services.

Based on the standard cloud computing model, where a service provider sells services to anyone via the internet. These services might be free, or offered as a pay-per-usage plan.

Benefits:

• Easy and inexpensive set-up • You pay for what you use • Ability to adapt to meet your needs