Everyone in the IT industry is talking about cloud computing, but there is still confusion about what the cloud is, how it should be used and what problems and challenges it might introduce. This FAQ will answer some of the key questions enterprises are asking about cloud computing.
- What is cloud computing, and can it be trusted?
- How is cloud computing different from utility, on-demand and grid computing?
- Is cloud computing the same as software-as-a-service?
- Can software-as-a-service actually improve security?
Cloud computing is "a style of computing in which massively scalable IT-related capabilities are provided 'as a service' using Internet technologies to multiple external customers." Beyond this definition, clouds are marked by self-service interfaces that let customers acquire resources at any time and get rid of them the instant they are no longer needed. The cloud is not really a technology by itself. Rather, it is an approach to building IT services that harnesses the rapidly increasing horsepower of servers as well as virtualization technologies that combine many servers into large computing pools and divide single servers into multiple virtual machines that can be spun up and powered down at will.
Cloud by its nature is "on-demand" and includes attributes previously associated with utility and grid models. Grid computing is the ability to harness large collections of independent compute resources to perform large tasks, and utility is metered consumption of IT services, says Kristof Kloeckner, the cloud computing software chief at IBM. The coming together of these attributes is making the cloud today's most "exciting IT delivery paradigm," he says.
You might say service kicked off the whole push toward cloud computing by demonstrating that IT services could be easily made available over the Web. While SaaS vendors originally did not use the word cloud to describe their offerings, analysts now consider SaaS to be one of several subsets of the cloud computing market.
Software-as-a-service allows companies to cooperate with business partners without exposing their internal networks. "A lot of companies don't want those people wandering around inside their firewall." Another beneficial side effect is that software-as-a-service can give companies the off-site backup of data required by various government regulations.