AutoCAD for Mac 2012 can be installed using the AutoCAD 2012 for Windows serial number and product key however you cannot install AutoCAD 2012 for Windows using the AutoCAD for Mac 2012 serial number and product key. Yes you can open older version PC drawings on it. I have 2011 on my Mac and 2010 on PC and it has had no problem with transferring drawings form the PC to Mac. The file extension is DWG. This is pretty much the same program the only difference is that it is on Mac. Whatever you can do on the PC with AutoCAD you can do in the Mac version.

• DWG™ compare: View and document the differences between 2 versions of a drawing or xref. • PDF import: Import geometry (SHX font files, fills, raster images, and TrueType text) into a drawing from a PDF. • Attach/extract point cloud data: Attach point cloud files acquired by 3D laser scanners or other technologies to use for your designs. • Save to web and mobile: Save drawings from your desktop to view and edit on AutoCAD web and mobile apps.

• High-resolution monitor support: View your designs on 4K- and higher-resolution displays.