The great buzzword of our time is “the cloud”. Companies are moving to it, or they are talking about it. Some of the largest companies in the world use it. Big names like “Google”, “Amazon” and “Microsoft” will sell you their cloud. But what is it?
Answering that question completely is difficult. But we can make a start. Most of the time, the cloud is simply someone else’s computer. On top of that is an interface that controls access to the resources. This is what allows you to create virtual machines, upload and download data and work with whatever services the provider offers. It is also where the provider tracks your usage for billing purposes. In some ways this is not very different from using VMware or HyperV to manage your machines. Indeed, there is a continuum from locally hosted virtual machines to cloud hosting. The important distinction of a “cloud” is that someone else worries about the hosting details. All you need to worry about is building and configuring your virtual machine.
Now, why would you want to use “the cloud” to host your computing? One reason is that your computing needs are only temporary. For instance, you may need to process a large batch of data. However, you are only going to do this once (or once a year). Sure, if you have spare computing power on-site, you can just use it. But otherwise, the cloud offers you the option of creating as much computing power as you want, then destroying it. This can be a lot less than buying a new computer for a single purpose.
Another, classic, reason is a great variation in your workload. This is an extension of the previous idea: every so often, you need to use a lot more computing power. Often, this is unpredictable, but when you need it, getting it is vital. The cloud is a great solution to this sort of problem.
By contrast, if you have a predictable workload which does not vary, you can simply buy the right size computer to fit your needs. This could well be cheaper than hiring the same computing capacity from a cloud vendor. This is where you need to do your cost-benefit analysis to see which option suits you best.
There is a lot more to cloud computing than just this, and I may address these other topics in future posts.