The powerful new search and organization features in Windows Vista make extensive use of the properties (called metadata or keywords) associated with the files you store on your PC to provide you with dynamic ways to view your content. These properties can include things like the date a file was created, the author of a file, names of people who appear in a photo, or the application that was used to create the file.
For example, Microsoft Office automatically saves certain information on documents that you create, such as your name and the date the document was created. When you add music to your PC, information such as song name, album, and artist are added to the actual music file. With Windows Vista, some of the most useful pieces of information are the keywords that you apply to your saved files. Tagging your files with keywords is fast and easy, and can be applied to a single file or to a group of files all at once.