Every NVIDIA driver has two version numbers -- which is the real one?

[jhsachs]

When I display the driver version in Windows Device Manager I get a four part release number like 21.21.13.7892. When I display it in nvidia-smi, I get a two-part number like 378.92 (the same last five digits, differently formatted). When I display it in GPU-Z, I get something like "21.21.13.7892 (ForceWare 378.92) / WHQL Win7 64."

Why the two different forms, and which one is the "real" number?

And who or what is ForceWare?

 

[13thmonkey]

what does 'real' mean, but the one that you can identify a driver by is the short one, when you try to download historic drivers this is the one that is used to choose them.