Microsoft SQL Server Database Basics
Appendix C: Backup and Recovery Best Practices 109
Example
The following diagram illustrates a database with six user-defined Secondary
Data Files (.ndf) grouped in two user-defined FileGroups and stored on three
separate disks. You can create a table on each FileGroup so that any queries
against the data in a table can then be allocated across the three disks in parallel,
to improve performance. Note also that the Transaction Log and Primary Data
Files are stored separately from user data.