This is a combination package of Microsoft Visual Studio Professional 2010 and Visual Studio Professional 2012. The Microsoft license we provide will allow you to install and use Visual Studio Professional 2010 AND Visual Studio Professional 2012. This can be useful if you are developing an App using a 3rd Party SDK and VS Plugin that currently only supports VS 2010 so you need Visual Studio Professional 2010 now. But only until they update it to VS 2012, at which point you can switch to Visual Studio Professional 2012. If you buy our Microsoft Visual Studio Professional 2010 And 2012 Combo, we will supply you with a licence to cover the use of Visual Studio Professional 2010 and Visual Studio Professional 2012. You download the software for Visual Studio Professional 2010 and Visual Studio Professional 2012 from a secure Microsoft website.