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This allows the server to be available over the Internet or by tunneling the Remote Desktop
Protocol data over a secure HTTP session.

Software as a Service (SaaS)
For some applications, you may not even need to have the software installed on your servers
at all. This is another way that equipment can be eliminated from your company—just don’t
install the software to begin with.

Characteristics Software as a Service (SaaS) is a model where a software vendor offers
its software for use over the Internet. You don’t house any of the equipment needed to
run the software; you simply log on with the provider and run the software virtually.
Also, you don’t pay to own the software. Instead, you simply pay whatever fees are
charged to you.
Another upside to SaaS is that you don’t have to worry about buying upgrades to the
application, performing upgrades, and troubleshooting any problems. Any upgrades are
performed by the SaaS provider.
According to IDC, key characteristics of SaaS software include the following:

• Network-based access to, and management of, commercially available
software.
• Activities that are managed from central locations rather than at each customer’s
site, enabling customers to access applications remotely via the Web.
• Application delivery that typically is closer to a one-to-many model (single instance,
multitenant architecture) than to a one-to-one model, including architecture, pricing,
partnering, and management characteristics.
• Centralized feature updating, which obviates the need for downloadable patches and
upgrades.
SaaS applications are priced on a per-user basis. Additional fees can be added for extra
bandwidth and storage. Revenue for SaaS vendors is generally smaller up front (as compared
to buying licenses and selling software packages), but much larger on the back end as
companies subscribe to the service.

ASP Differences This concept may not sound new, especially if you have been using
application service providers (ASPs). But SaaS is different from an ASP. It’s easier to think
of SaaS as ASP version 2.0. PART V
ASPs host applications on behalf of their clients. But ASPs generally don’t create their
own applications. SaaS vendors, however, create their own applications and run them on
their own.