The MSSQL server actually hosts the database. This is makes it similar to the file manager portion of Windows. No Window program directly accesses the files on the hard drive, the program requests the file from the file manager and it then opens the file for the program. The program doesn't care where the data is actually stored on the hard drive. With ACT! 6 and before, ACT! directly managed the storage and retrieval of information in the ACT! database. The result was that performance declined rapidly as the database became larger. With MSSQL, ACT! is relieved of knowing how the database information is stored and much large databases can be used without the decline in performance.