The only case with hard drives where the USB standard matters much is if you connect a drive to an old-style, low-bandwidth USB 2.0 port, which is better reserved for items like keyboards and mice.

A hard drive or solid state drive (SSD) that resides outside the computer's case, typically connecting via USB or eSATA. A USB flash drive is also external storage. See portable drive and USB drive.

Yes. I cannot think of any scenario where it wouldn't be the case and just to confirm, we're talking of portable hard drives (the ones that can be carried around, smaller cousins of desktop or ...