Cloud computing is the ability to access a service remotely, generally using an internet connection, that traditionally either existed on your home personal computer or on your company’s own network. The reasons for cloud computing as opposed to the traditional model are reasonably simple; cost and flexibility. Because you are effectively chipping in with thousands, or millions, of other users, the cost to deliver that service to you are massively reduced. Flexibility is king, with cloud services able to be accessed from virtually any device that has an internet connection.
Chances are you are using the cloud already, if you have an Apple or Android device you certainly will be.
Services delivered on Cloud come in three general categories:
Infrastructure as a Service:
The lowest level of the stack that provides virtual servers, storage, load balancers, networks, and a host of other pure iron components. As an end-user, you’re not likely to ever see this. Mozy, DropBox, SkyDrive, and all other applications will ultimately leverage off this service.
Platform as a Service:
This layer provides a virtual platform up to the server level (usually), with perhaps a database and / or middleware applications added. Examples of this service would be Microsoft’s Azure or Google’s App Engine.
Software as a Service:
This is the consumer level of cloud for want of a better word. The Xero’s of the world, Apple iStore, Google App Store, Salesforce, and so on. Any software application that can be run as a cloud service that you access via a browser.
Cloud comes in four deployment models with a fifth appearing in the past week or two:
A cloud that is generally available to the public and often free. Others have some usage based charging. Examples would include Hotmail (free) or Microsoft 365 (subscription based). Public cloud is generally perceived as less secure, though this is not always true. It is usually the cheapest. It also raises issues of Data sovereignty for Governments. I.e. If I am a government agency in New Zealand, is it ok for all my data to be stored in the United States?
This cloud shares infrastructure between several different organisations but is still managed by a third-party provider. The United States, Japanese, Canadian, Indian, Irish, Australia, and New Zealand Governments are either well done the path of deploying community clouds between various agencies within their states or are investigating actively how it can be used.
A combination of the various cloud types.
A cloud that is deployed for a single organisation, either from within their own infrastructure or delivered by a third-party.
A new term that may or may not “stick”. Recently the Apple iCloud was “hacked” and received a lot of attention due to the fact that the victim was in the media. Soon after that hack, a lot of the cloud service companies began to use the words “consumer clouds” in an effort to differentiate their offerings from the perception of a security risk. The reality is that the “consumer cloud” is no different to a public cloud.
There are a number of risks around the cloud with security being the most frequently raised. In addition, data sovereignty risks appear, there are risks associated with vendor “lock in”, what happens if a cloud provider fails (Megaupload), and the ability for foreign governments to legally access data.