If you own an Apple iPad, statistically, the odds are you own an iPad 2. There’s no shame in that. Your four-year-old tablet is probably on your coffee table, or next to your bed. Maybe it’s in your briefcase, full of movies for your flight tomorrow. Perhaps you’re thinking about upgrading to the new 9.7-inch iPad Pro. There are many new features (and limitations) that only show up in the iPad Pro. Here’s what you should know.