Next Generation file system storage built on NTFS for the next version of Windows - Longhorn. More information about it can be found at the Longhorn Developer Center

What does WinFS stand for?

WinFS is a relational file system (as it is positioned) but it doesn't mean that you can get the hard disk drive and format it in WinFS. No. Instead WinFS uses NTFS as underlying platform and reuses SQL Server 2005 functionality with CLR integrated into it that provides us UDTs as .NET classes. All the data stored in WinFS must be one of the types either described in the assemblies installed with WinFS (.NET classes as UDTs are described as XML schemas and stored in assemblies) or in 3rd party assemblies provided by other companies as well. That means that anything stored in WinFS is a special class and so all the data is structured one. All data is stored in SQL Server and NTFS. Why so? The problem is that SQL Server provides an opportunity to save data that is simple to search for and retrieve from server. But there are some kinds of data that can't be recognized and stored in SQL Server like media files. Say you can store some data about media file and then perform a search against it but it is not possible to search for the media part (sound or sound composition) using text search - there is no such mechanism to describe sound in text. Instead you can store some data about this sound (or any other type of media file) and this "data about data" is called metadata. Metadata already exists that mean that you can store some information about tracks (MP3 tags) or documents (Word Documents Properties like Author, Comments, and Revision etc.). The second problem is that not any file has metadata in its format. Say you can add metadata to Photoshop media file but there is no way to add some data for text documents in txt format. WinFS brings a standard way to describe data items of different types (Contacts, Documents and so on) and a standard way for storing and adding metadata for them. In fact WinFS stores anything that can be used in search in it while the data that can't be retrieved by particular search (say you can't query for the sound track itself, instead you can query for its name etc.) is stored in NTFS. WinFS brings the opportunity to work with data as with OOP objects (.NET classes) that makes data management even more powerful than it is available as of now. After WinFS installation you'll notice some changes - you'll find some new shell namespace extensions that would be stored in My Computer folder. They will provide you an access to data stored in WinFS in a simple way. Say extension for Contacts would be "Personal Contacts" extension in My Computer, for Documents - "Documents", for videos and pictures - "Pictures & Videos" you've got the idea. There are some ways to retrieve similar types of data from the file system itself by using such mechanisms as Windows Desktop Search but they are not such powerful as WinFS. The difference is that while WinFS stores data (say files) in it itself tools like Windows Desktop Search (and Windows Search in Windows Vista) index existing files stored in the particular file system (NTFS) and the actuality of the search very hard depends on the period of re-indexing time. WinFS performs the search across the data itself against those tools that search against the indexed image of actual data. This is the very big difference between traditional file search utilities and WinFS.

Also WinFS provides a powerful mechanism of relationships between different data stored in it. First of all it is very important to understand that WinFS presents the new abstraction for data management named Item. Anything in the world that can be described in text terms derives from Item. Say apple is type of fruit and fruit is type of Item etc. So WinFS makes it easy to relate different types of data like Documents and Contacts. You can relate them by themselves (say Document.RelatedContacts retrieves you the collection of related contacts) or relate by their properties (say Document.RelatedContacts retrieves you the collection of the contacts if the Document property Author contains the names of those contacts). This features a new way of interacting with data. Say you are going to find someone in your Personal Contacts folder. You’ve found it (simply by listing the whole collection of contacts stored in your machine, or by input of a number of filters) and now you will be able to query for related items like Documents (this contact sent you), Media items (this contact listen to), Emails (this contact sent you) and so on. You will click on of the Documents related to this contact and the appreciate application starts and opens this document. WinFS doesn’t know what that application is instead the WinFS storage watcher does all that work and runs the related application.

Also WinFS provides such great features like synchronization between different data silos to it. All these features makes WinFS the best way to store and manage data in your computer.