How to use product versions?

Hello Sir,I want to know exactly what is the use of creating the versions?How to use versions effectively?Please guide? If possible please give example?

You use product versions to organize your products vs. versions withn a product.

For example, Microsoft Office is a product. And there are separate version (MS Office 2010, MS Office 2013, MS Office 2012 for Mac OS X, etc., etc.). Each of the separate product version has its own serial numbers that can't be used for other product versions.

Does that make sense?

Yes, thank you.