Cloud Computing is a subject about which the computing world propagates smoke and mirrors.

Quite simply, ‘A Cloud’ or ‘The Cloud’ is nothing more or less than a computer network. They are one and the same. If anyone ever tries to tell you different tell them to call Cloud expert Graham Doyle.

Two PC’s connected together with a piece of wire can be called a computer network. It can also be called a Cloud. End of story. Well almost…

Of course, there are some additional attributes that tend to be associated with the term “Cloud”, such as ‘resilience’, ‘high-availability’ and ‘IT as a Service’. These additional attributes become possible because of the size of the computer network, the number of connections, and the software used to control it - but the basic principle is the same as two PC’s connected together with a piece of wire.

A cloud can be public or private. An example of a public cloud is the Internet. Other examples are Amazon's 'EC2 Cloud' and VMware's 'Redwood Cloud'. Both of these are merely computer networks but they have lots and lots of computers connected to each other, often with multiple connections to each computer, and some clever software to control the use of services within their public Cloud's. More about these in future posts...

What that means is your stuff can be moved around the cloud, and it’s always accessible. Your stuff can even be in multiple places at the same time.

So, if one or several of the computers in the Cloud stop working, you can still access your stuff because it’s replicated in multiple locations. This is what is meant by resilience and availability.

In theory, the Internet can withstand any disaster, whether natural or man-made, because the network (or cloud) is so big that even if parts of it stop working, the Internet as a whole keeps working. There is no single point of failure anywhere. So if you have a device with an Internet connection, you can still access your stuff - from any device, from any location, any time.

An example of a private cloud is your own computer network at home or at work. These clouds tend not to have as much resilience and availability as a big cloud like the Internet, but a reasonable sized organisation can still build a lot of resilience into their own private Cloud.

One really good way to make the most of what Cloud Computing can offer is to use Virtual Computing. Virtual Computing and Cloud Computing are often confused but they are completely different technologies. Watch out for our articles about Virtual Computing to find out more.

Another really good way to make the most of Cloud Computing is by using “IT as a Service”. Watch this space as next time I’ll be de-mystifying IT as a Service.

Click here for more about Cloud Computing and Virtual Computing.