There are many meteorological pun’s associated with the term “cloud computing”. The term represents a huge paradigm shift in the way backend software services are delivered.
This article covers much of the confusion associated with this ambiguous and overused phrase.
From a software developer perspective, the deployment model and elasticity are the key differentiators for cloud services.
I consider a cloud service to be a system that can host my software and hide the complexity of the server farm (e.g., routers, load balancers, SSL accelerators, etc.).
Amazon popularized the term “Elastic Cloud” when they launched their core cloud component called EC2 back in August 2006. EC2 stands for Elastic Compute Cloud (EC2). Elasticity is the infrastructure’s ability to automatically scale up and scale down as needed.
Elasticity is a big deal. It dramatically simplifies the deployment and administration process. It means that software developers don’t need to worry much about infrastructure as much and can focus on coding the business process.
I consider Amazon, Google and Microsoft to be the big 3 cloud vendors. They have the elasticity expertise and server farms to support high volume cloud apps.
There’s Oracle, Salesforce.com, Rackspace and others but IMO are not generic cloud platforms.
For more about the non-developer cloud computing perspective, this Wikipedia article is a great reference.
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