When you attach a Windows keyboard to a Mac, all of the modifier keys are mapped to the corresponding Mac modifier keys: This compatibility is also handy if you already have access to a Windows external keyboard, for example if you’ve recently made the switch to a Mac, then you can just plug your old Windows keyboard into your new Mac and start typing away.
The good news is that your Mac will work with any USB or Bluetooth keyboard, so when you’re shopping for an external keyboard there’s no reason to limit yourself to keyboards that were designed specifically for Macs. In addition, external keyboards that are designed specifically for Mac tend to be more expensive than their Windows counterparts. However, there isn’t a huge number of external Mac keyboards out there, particularly compared to the number of Windows keyboards currently on the market. While every MacBook comes with a built-in keyboard, many users opt to use an external keyboard instead, either because they find it easier to type on a full-sized keyboard, or because the angle of their laptop’s built-in keys gives them wrist strain.