One of my course participants came back to me after I wrote about “public and private cloud computing“. His company runs a service where his customers access their digitized paper files. The service runs on servers that they deploy from a hosting provider.
Because of this, they can promise their customers that their data will be in a specific geography. For compliance reasons his customers need this. Customers working from a different geography might work from different servers.
Now, what kind of cloud computing is this? His company has servers dedicated to him.
His customers however are working on shared servers, if they are in the same geography.
There are actually two cloud situations at work here. His customers are using SaaS, as they use an application that runs on shared resources, and they can adjust their usage by self-service. They don’t control the infrastructure, so to them it is a public cloud service. SaaS is oftentimes not tied to a specific geography, but although cloud computing requires services to be broadly accessible, it is not required that the service is replicated all over the world.
His company however is using something that looks like IaaS, and as the servers are dedicated to them, you could categorize that as private cloud. Though, as the provisioning of these servers requires manual intervention by his provider, it is doubtful whether you should be calling it cloud computing rather than hosting.