Moderator-80-
I’m afraid that’s not correct.
As popularly used the terms mean:
“usb drive” – a small solid-state flash memory device.
“external drive” – a standard hard drive, enclosed in a case. Can be connected to a PC via USB cable or (sometimes) to a network via a router port.
External drives may or may not require an additional power source – most draw what they need from the USB cable.