"Cloud computing" is a buzzword that’s tossed around a lot these days to describe the direction in which information infrastructure seems to be moving. The concept, quite simply, is that vast computing resources will reside somewhere out there in the ether (rather than in your computer room) and we’ll connect to them and use them as needed.

Google, naturally, is a big promoter of this idea, as its business is already based on owning a massive computer infrastructure (or cloud) that people tap into from their homes or offices. Recently Google even joined with IBM to promote cloud computing – and for anyone familiar with the history of information technology, that should be a bright red flag.

There’s nothing wrong with the idea of cloud computing. In fact, it’s sufficiently compelling that in large measure it already exists. My company doesn’t own any servers, and for the most part we have only basic productivity software on our personal computers, with everything else off in a cloud.

Our website lives on a server at our hosting company, a local firm called Modwest. Our sales management system is on computers owned by Salesforce.com. We have subscriber and survey data on machines run by Survey Monkey. And yes, we use Google, for search and for analytics and for document sharing, among other things. I could go on.

This is all good from our standpoint; we have no desire to buy and maintain lots of computers and software. If we can let someone else worry about the basic technology, we can focus on the publishing. Any businessperson can see the logic of that.

The flip side, though, is that you’re dependent on someone else for your technology, and that can limit your flexibility and even your creativity. In fact, the personal computer itself arose because the old model of business computing, in which companies had big mainframes (aka clouds) and everyone connected to them via "dumb" terminals, was enormously frustrating for the people sitting at those dumb terminals.

They could only do what they were authorised to do. They were dependent on the computer administrators to give them permission or fix problems. They had no way of staying up on the latest innovations. The personal computer was a rebellion against the tyranny of centralised computing operations – and of the IBM mainframe world in particular.

With cloud computing, we have come full circle: the efficiencies of a centralised computing infrastructure that can be easily accessed via the internet are just too compelling to ignore.

But I would argue that a centralised computing infrastructure run by Google and IBM is anything but an optimal scenario for most companies and individuals.

On the one hand, such a cloud would likely have even more killer services at very low prices; Google has certainly proven its ability to deliver value in that regard.

On the other hand, over the long run the lack of flexibility inherent in someone else running your tech will become a problem again. You’ll be able to get any kind of software or service you like for a very low price – as long as it’s a piece of software or service that Google and IBM think is appropriate. (Since economies of scale are at the heart of the cloud computing advantage, there is every reason to believe that Google and IBM together could achieve a very dominant position.)

When Google talks up the benefits of cloud computing, what the company is really saying is, use our cloud rather than the various ones you’re using now. Let us host your applications, let us host your website, let us take all those different services you use and simplify them and make them cheaper and better. It’s not a bad argument.

Personally, though, I like having a website hosted around the corner by people I know and can call personally if there is a problem. Maybe it’s a few bucks extra a month, but I like at least having the option.

Indeed, what’s best for the customer in the end is having plenty of choices. Cloud computing can be a great thing, but I hope there continue to be plenty of clouds to choose from, and not all of them run by Google.

Cloud computing is a way of computing, via the Internet, that broadly shares computer resources instead of using software or storage on a local computer.

Cloud computing is an outgrowth of the ease-of-access to remote computing sites provided by the Internet.^[1]

In concept, it is a paradigm shift whereby details are abstracted from the users who no longer have need of, expertise in, or control over the technology infrastructure "in the cloud" that supports them.^[2] Cloud computing describes a new supplement, consumption and delivery model for IT services based on the Internet, and it typically involves the provision of dynamically scalable and often virtualized resources as a service over the Internet.^[3][4]

The term cloud is used as a metaphor for the Internet, based on the cloud drawing used to depict the Internet in computer network diagrams as an abstraction of the underlying infrastructure it represents.^[5] Typical cloud computing providers deliver common business applications online which are accessed from a web browser, while the software and data are stored on servers.

A technical definition is "a computing capability that provides an abstraction between the computing resource and its underlying technical architecture (e.g., servers, storage, networks), enabling convenient, on-demand network access to a shared pool of configurable computing resources that can be rapidly provisioned and released with minimal management effort or service provider interaction."^[6] This definition states that clouds have five essential characteristics: on-demand self-service, broad network access, resource pooling, rapid elasticity, and measured service.^[6] Narrowly speaking, cloud computing is client-server computing that abstract the details of the server away – one requests a service (resource), not a specific server (machine). However, cloud computing may be conflated with other terms, including client-server and utility computing, and the term has been criticized as vague and referring to "everything that we currently do".^[7][8][9]

The majority of cloud computing infrastructure, as of 2009

^[update]

, consists of reliable services delivered through

data centers

and built on servers. Clouds often appear as single points of access for all consumers’ computing needs. Commercial offerings are generally expected to meet

quality of service

(QoS) requirements of customers and typically offer

SLAs

.

Cloud computing is all the rage. "It’s become the phrase du jour," says Gartner senior analyst Ben Pring, echoing many of his peers. The problem is that (as with Web 2.0) everyone seems to have a different definition.

As a metaphor for the Internet, "the cloud" is a familiar cliché, but when combined with "computing," the meaning gets bigger and fuzzier. Some analysts and vendors define cloud computing narrowly as an updated version of utility computing: basically virtual servers available over the Internet. Others go very broad, arguing anything you consume outside the firewall is "in the cloud," including conventional outsourcing.

[ Learn how early adopters of cloud computing have used the technology and the lessons they have learned. | See how Amazon, Google, and other cloud platforms stack up in the InfoWorld Test Center's comparison. ]

Cloud computing comes into focus only when you think about what IT always needs: a way to increase capacity or add capabilities on the fly without investing in new infrastructure, training new personnel, or licensing new software. Cloud computing encompasses any subscription-based or pay-per-use service that, in real time over the Internet, extends IT’s existing capabilities.

Cloud computing is at an early stage, with a motley crew of providers large and small delivering a slew of cloud-based services, from full-blown applications to storage services to spam filtering. Yes, utility-style infrastructure providers are part of the mix, but so are SaaS (software as a service) providers such as Salesforce.com. Today, for the most part, IT must plug into cloud-based services individually, but cloud computing aggregators and integrators are already emerging.

InfoWorld talked to dozens of vendors, analysts, and IT customers to tease out the various components of cloud computing. Based on those discussions, here’s a rough breakdown of what cloud computing is all about:

It’s soon to be lights out for the free home page service, purchased for a steep price during the dotcom boom.

Yahoo is shutting down GeoCities, a free service that hosts personal home pages for consumers, which it acquired for more than $4 billion 10 years ago during the heyday of the dotcom boom.

A posting on a Yahoo (NASDAQ: YHOO) Help page for GeoCities on Thursday said the service was no longer accepting new customers and that it will be closing later this year, with more details about how individuals can save their data coming this summer.

The move comes a few days after Yahoo said it would lay off nearly 700 workers, or 5 percent of its workforce.

Since CEO Carol Bartz took the reins in January, Yahoo has pruned various products and properties to cut costs and focus on fundamentals, as it seeks to revive growth in a tough economy and fierce competition from Google Inc.

Last week, Yahoo said it was shutting down Jumpcut, an online service for editing videos.

Yahoo acquired GeoCities in 1999 in a stock deal valued at roughly $4.6 billion, Reuters reported at the time.

GeoCities was among the first companies to build online communities, with more than 3.5 million Web sites hosted on its service in the late 1990s.

But GeoCities fell out of favor in recent years, as a generation of social network sites such as Facebook and News Corp.’s Myspace have become popular among Web users.

"We have decided to discontinue the process of allowing new customers to sign up for GeoCities accounts as we focus on helping our customers explore and build new relationships online in other ways," Yahoo said in a statement.

"As part of Yahoo’s ongoing effort to build products and services that deliver the best possible experiences for consumers and results for advertisers, we are increasing investment in some areas while scaling back in others."