example: If I were to purchase a lesson video like this product from ChessBase, how do run and learn from it using a Mac ?
Chessbase once tried to make a Mac version. It was buggy and under-featured, so didn't sell, and rather than improve it they gave up on ever doing one. How to play it on a Mac depends on what your computer skills are. Not sure if chessbase reader (the app you'd use to play it) runs under WINE these days, but that would be one option (cheapest but requiring most skills). A second option would be a free virtual machine system (VirtualBox) with windows installed on a VM. The easiest (and also most costly, funny how those two go together) is a system like Parallels or VirtualPC.