RSS – How Does It Work?

Yesterday, I looked at how people may be using RSS (Really Simple Syndication) without knowing it as well as how it might help make your consumption of digital information more efficient.

Despite its name, people may think that RSS could be rather complicated but with a little time and understanding I reckon most people could figure it out without too many problems.

RSS is based upon XML (eXtensible Markup Language) which are plain text files. These text files contain a hierarchy of elements which exist in a particular order and possess specific qualities that dictate the type of information they can contain.

Here is an example of the XML underlying RSS to give you an idea of its presentation:

Example RSS XML

As you can see, the elements should be fairly self explanatory (and if you want a detailed explanation of each element you can check out the RSS 2.0 specification). At the top you have a prologue declaring the XML version followed by the RSS root element which also declares the RSS version (2.0) with several nested layers of elements underneath. Elements consist of start and end-tags which essentially form a wrapper around a value or other nested elements. You might like to think of it along the lines of how you might organise folders and files on your computer with the root element being similar to the C Drive on a Windows machine.

In the above example, the RSS only contains one channel with numerous items within that channel but an RSS feed can contain more than one channel without too much effort so long as the nesting is kept in compliance with the specification. Most blog and forum software include automatic RSS feed generation so you won’t need to hand craft it at all.

RSS feeds exist as XML files on a web server which RSS readers consume every so often (the refresh interval can be set globally or per feed in the more mature readers). In general, an RSS reader will then make a comparison between the most recent RSS XML document and its cache and import the difference.

Hopefully, that gives you an idea of how RSS works at the high level and perhaps slightly peel back some of the “shroud of mystery” at the same time.