Defining Platform as a Service (PaaS)

I was in Bangalore during last couple of days to deliver a speech at BTSummit.The word PaaS was mentioned in one of the leaflets there & suddenly the guy seated next to me asked what it stands for. I thought of my explanation to him might be useful to others as well. So here it is.

PaaS is an outgrowth of the Software as a Service application delivery model(SaaS). (See my definition of SaaS).

In PaaS model, one hosts a complete platform (eg: starting with an OS, application runtime, perhaps with option of several database engines, selected set of server runtimes) & allows multiple business entities to use it (usually for a fee - it has to be business ;-) ).

Usually these platforms can be scalable. So the business entities can request for more resources as their requirement grows.

A good example can be a temporary test bed for an application your company is developing. Say you are developing some application & want to load test it with some enormous configuration. Obviously your IT department does not have that amount of spare CPU power, machines, etc. Renting out a hosted platform is ideal in this case.

Thus, the 'Platform becomes a Service'.