Hi,
It would be useful when your product, i mean your application has muiltiple dll's. File version refers to the dll version and the product version refers to the overall application version.
Ex;
My Application Ver 1.0
- Str.dll Ver 1.3
- Bool.dll Ver 1.2.1
My Application Ver 1.1
- Str.dll Ver 1.3
- Bool.dll Ver 1.3
Regards,
Siddu