some questions about cloud computing and web hosting?

Is this application on cloud?

One of my comapny's web application software service is provided to many different clients over internet which is nothing but SAAS(Software as a service ) model which is one of the aspect of cloud computing.Can I say this application hosted on cloud ?

Another related question is this application web hosted or cloud hosted?

As per my understanding cloud hosting and cloud computing both are same thing. Correct ? For information this application is hosted on Sunguard Datacenter where if application is hosted on dedicated server and if one server goes down, another backup server will start serving the request

As per various links on internet like this, if application is hosted on single server which is shared with other application then it is called web hosted but on the other hand if application is hosted on single dedicated server (where if this server goes down another will start serving the request) then it is called cloud hosting. Is that correct? I believe most of the datacentre provider provides provides both cloud and web hosting.

Solution

Answering your first question: No, your application is not hosted on Cloud. AFAIU, what your company has done is, rented some hosting space and hosted your software/application there. I dont know who takes care about the deployed app etc. If it is also done by the company, then it is definitely not cloud hosted.

If your application to be said cloud hosted, it needs to fullfil some requirements. For example,

It should have high availability. i.e. if the server goes down, there should be automatic failover and you should not worry about it.
Auto scalability - i.e. If your app starts getting a high load, the infrastructure should be able to scale up automatically rather than you having to spin up new instances.
There should be periodic backups which will allow you to recover from an unexpected failure and restore to a known point.

Even your app is hosted in a shared server, if the cloud provider can provide isolation to your app, that is good enough if it can guarantee the above requirements.

Basically, if your app is cloud hosted, its very little you have to worry about it.