SaaS, SOA, Web 2.0 ...

There are a plethora of terms ... And, if you ask me, I am confused. So, a little bit of thinking, and I am trying to get to the root of some of these terms. Of course, this would, by no stretch of the imagination, be anything authoritative, but a little effort.

The way I see it, SOA and SaaS are related concepts ... Cant have one without the other. Software as a service can be provided only with an architecture that is oriented towards the service approach to software. So far, we are ok. Now, coming to the web 2.0 piece, in terms of technology ... At the core, I think the two are related. While SOA and SaaS are talking about the technology infrastructure to make software more flexible, and to ensure the software can mould itself to changing business requirements, web 2.0 is doing the same thing at the front end level. In other words, basically, web 2.0 is what you see, and SOA and SaaS are things the developers who are developing these applications see. So, in a sense, these concepts are related, and are components of a single jigsaw which is emerging as we go along.

For example, google has come up with OpenSocial, and Facebook has already done this. And, mashups are a part of the emergent jargong. None of these would have been possible without the componentization of software which is something SOA claims to achieve. Though, to an extent, I think this is essentially old wine in new bottles, but the fact is, there has been talk of modularity in software design for quite some time now, and SOA take this one step further. Of course, this is quite devoid of the technical aspects (much of which I dont know), but just thought would put thoughts together to bring these to a point where they are seen as being aspects which are complementing each other.