If the cable from your external display, hard drive, camera, or other device doesn’t connect to the Thunderbolt 3 (USB-C) or USB-C port on your iMac Pro, iMac, MacBook Pro, or MacBook, you might need an adapter.

Apple has a tech support article describing many of the connected types you may want to use.  While this article is not completely comprehensive everything available, it’s a great place to start.