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 "http://www.gartner.com/" target"_new" 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.

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 "http://www.itpro.co.uk/cloud" target="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 "http://csrc.nist.gov/groups/SNS/cloud-computing/" "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.

Businesses may well be using some, or all, of these services already. Hosted Microsoft Exchange email or hosted SharePoint services, Google’s Docs product and software as a service applications - of which Salesforce.com is perhaps the best known - show the range of services on offer through the cloud.

Increasingly, cloud computing is being used as a byword for bought-in IT services that stop short of full outsourcing deals, involving long-term contracts and the transfer of equipment or staff.

In practice, cloud computing can be defined as technology – including software and hardware – that is owned by others, run remotely from the end-user business, and paid for through a flexible contract.

That pricing model could either be a subscription, per user, per month, or a form of pricing based on IT capacity or even transactions. Consumer services such as Mozy, an online backup service, have already set an example for this, by charging end users per gigabyte of storage they rent.

The cloud in practice

Inevitably, definitions will star to blur, as businesses, and vendors, put the emerging infrastructure to new uses. One business might well use a cloud service to provide a service, in turn, to others; there are already examples of companies building suites of hosted applications, using cloud technologies, for vertical markets such as law firms or estate agency.

At the other end of the spectrum, large enterprises and public sector bodies are going about creating their own, private versions of cloud computing. These use many of the same technology building blocks as public clouds, and even some of the same economic models, through internal charge-back mechanisms.

By putting cloud computing infrastructure behind the firewall and within the control of the IT department, some of the difficulties around security, privacy and data ownership are overcome.

The variety, and potentially the sheer size, of the cloud computing market is also prompting new services to develop, such as cloud brokers – who source cloud computing resources for businesses – and companies that are building technology to connect a business’ various cloud applications and create a common data set.

This, in turn, highlights a number of potential drawbacks to the cloud.

There are little in the way of formal standards governing cloud services, and especially, the way they categorise and store data. According to "http://www.itpro.co.uk/626437/cloud-computings-murky-future"PA Consulting, a lack of interoperability between cloud services could be one of the greatest barriers to their adoption by enterprises, perhaps an even greater barrier than data security.

None the less, all the signs are that cloud computing is here to stay. The onus is on IT departments to integrate the technology with their companies’ broader technology requirements, so that the business can gain the benefits of flexibility, lower costs and quick development times offered by the cloud.