The XenForo area is one small category of it (it's an overall digital goods marketplace), which you can see a few things of my own I've added here: https://marketplace.digitalpoint.com/xenforo.12/category
So what is it exactly?
It's a system to allow people to sell digital goods like addons, and the system handles everything about the transaction. You create the product page, upload the latest version and you more or less are done.
Things it handles...
- Payments (via PayPal)
- Licensing (license period is set by seller) along with optional license renewals
- Distribution of product once purchased
- Optional built-in affiliate program
- Multi-tiered pricing (for example you could give discounts or make it free to premium users)
It also does some fancy things...
Fully supports product, review and offer microdata, which means people finding your product page via Google search results will see things like the rating and number of reviews right in the Google search results (attracts extra attention). Example: http://www.google.com/webmasters/to...formula-make-money-within-hours.14/item&html=
You can see analytics for your product page for the last month... where traffic is coming from, how many page views, etc.
What is it not?
It's not a "resource manager" like here at XenForo... it's main purpose is selling digital goods (while you can give stuff away for free as well, that's not really what it's designed for). You can't upload articles (well unless you packaged it as a PDF eBook or something) for example. It's also a much bigger scope than just XenForo stuff, so it's not purely a XenForo thing (it does addons for other platforms as well as completely different things like eBooks, Scripts, Templates, etc.)
Anyway... glad to finally have the site migrated to XenForo so I can start building the fun/interesting stuff now (like this).