A couple of months back I wrote a blog post entitled Microsoft, OData and RDF where I gave a high level view of the OData protocol and how it compares to RDF. I talked about linked data, triples and such like which may have been somewhat useful however jargon-heavy. Earlier today Dr Michael Hausenblas (blog | twitter) offered an analogy which I think is probably more useful and with Michael's permission I'm re-posting it here:
Imagine a Web (a Web of Documents, if you wish), which is not based
on HTML and hyperlinks, but on MS Word documents. The documents are all
available on the Internet, so you can download them and consume the
content. But after you’re done with a certain document that talks about
a book, how do you learn more about it? For example, reviews about the
book or where you can purchase it? Maybe the original document mentions
that there is some more related information on another server. So you’d
need to go there and look for the related bit of information yourself.
You see? That’s what the Web is great at – you just click on a
hyperlink and it takes you to the document (or section) you’re
interested in. All the legwork is taken care of for you through HTML,
URIs and HTTP.
Hm, right, but how is this related to OData?
Well, OData feels a bit like the above mentioned scenario, just
concerning data. Of course you – well actually rather a software
program I guess – can consume it (a single source), but that’s it.
from Oh – it is data on the Web by Michael Hausenblas
I believe that OData has loads of use cases but its important to understand its limitations as well and I think Michael has done a good job of explaining those limitations.