Interesting reading to download from Microsoft: Highlights of the WinFS Data Access API (http://www.microsoft.com/downloads/details.aspx?FamilyID=96fcf90b-4929-422a-8719-d711180fb2c0&DisplayLang=en).="/P">
This document (by Mike Deem) provides a quick look at the basic concepts of the WinFS data access API: objects based on schemas, powerful query support, and support for WinFS concepts such as relationships. An interesting reading to understand the technology.