What is cloud computing?

Cloud computing is one of the fastest growing, and potentially most disruptive IT innovations for a generation.

The move to cloud computing is being likened to the arrival of the personal computer, a move that changed the IT face of the industry, and how businesses use technology.

Within four years, worldwide spending on could computing is expected to reach almost $150 billion, according to analyst firm Gartner.

Gartner is seeing growth in both the number of businesses signing outsourcing deals, and the size of those deals. Cloud computing programmes covering a thousand or more users are becoming more common, as chief information officers (CIOs) see cloud computing as a strategic option.

For businesses with more complex needs – and more critical security requirements – moving all computing to the cloud might not be practical

Experts are predicting that some businesses will be able to run most, if not all, of their IT services in the cloud. Evidence from smaller enterprises and start ups support this, with businesses opting to rent, not buy, much of their IT. Laptops and a good-quality internet connection can replace much of the conventional infrastructure for managing data and carrying out business processes.

For businesses with more complex needs – and more critical security requirements – moving all computing to the cloud might not be practical. However, it is likely that almost all businesses will move at least some applications or services to the cloud. Many have already done so, though services offered by vendors such as Google and Amazon.

As with any new or emerging technology, though, the cloud is attracting hype. The potential of cloud computing has to be tempered with some practicalities.

Businesses might not have applications that are “cloud ready”, be prepared to hand over control of critical data, be comfortable with data security arrangements or even have the bandwidth to run large parts of their business remotely. These are some of the issues that IT PRO will be exploring in more depth in the cloud computing channel.

What is the cloud?

Cloud computing’s quick growth, and the fact that the cloud has emerged organically from a range of services provided by different vendors, rather than according to an industry standard, poses some practical considerations for IT professionals.

In some cases businesses will already be using cloud computing services, without defining them in that way; in others, vendors that have provided remotely accessed IT – itself a service that dates back to the 1960s – have added a cloud computing label to refresh an existing product. Elsewhere, though, businesses are using services such as Amazon’s EC2 or Microsoft’s Azure platform, which most industries observe represent “pure” cloud computing.

The most widely accepted definition of cloud computing comes from the US National Institution of Standards in Technology (NIST). NIST defines cloud computing as a “model for enabling convenient, on-demand network access to a shared pool of configurable computing resources”.

As NIST sees it, cloud computing can be divided into three main categories: software as a service, platform as a service and infrastructure as a service.

Software as a service

“The capability provided to the consumer is to use the provider’s applications running on a cloud infrastructure”, as NIST puts it. This includes applications such as hosted email or CRM.

Platform as a service

“The capability provided to the consumer is to deploy onto the cloud infrastructure consumer-created or acquired applications, created using programming languages and tools supported by the provider,” according to NIST. This includes environments such as Microsoft’s Azure, or Salesforce’s Force.com.

Infrastructure as a service

“The capability provided to the consumer is to provision processing, storage, networks, and other fundamental computing resources where the consumer is able to deploy and run arbitrary software… including operating systems and applications.” Examples include Amazon’s EC2 cloud platform.