IT systems are really a stack of different components:
- At the bottom is the infrastructure layer, the actual hardware that runs everything.
- Next comes an operating system, allowing software applications to easily access the hardware components.
- Finally, there is the application itself, providing a user interface and performing a specific purpose.
There are cloud offerings for each part of this stack.
What Is IaaS?
Infrastructure as a Service (IaaS) offers basic components, giving access to virtualized servers or storage so that end users can build systems from the ground up. Simplified, that means IaaS provides a virtual server that the customer rents from another company that has a data center. IaaS promotes access versus ownership and gives the end user flexibility when it comes to hosting custom-built apps while also providing a general data center for storage.
What Is PaaS?
Platform as a Service (PaaS) provides some sort of operating system, allowing end users to avoid some of the steps in organizing infrastructure and move right into software development. A PaaS provider offers a company physical IT infrastructure, such as data centers, servers, storage and network equipment, plus an intermediate layer of software, which includes tools for building apps. And, of course, a user interface is also part of the package to provide usability.
What Is SaaS?
Software as a Service (SaaS) is the final stage, providing an end user with a piece of software that typically runs in a browser rather than being hosted locally. This means software can be accessed from any device with an internet connection and web browser. Customers deploy SaaS offerings in a cloud deployment model, as described below.
These three basic offerings have spawned countless other “as a service” solutions. Part of the challenge involved with cloud computing is sorting through these many offerings and figuring out which ones are the best match for the company. Inevitably the end result will include pieces from multiple parts of the stack.
Along with the primary cloud service types, there are three primary cloud deployment models which I will be posting in my next post.