They’re the same port. TB4 is TB3 + USB4 + two display support (and maybe some other things?). The M1 isn’t compliant because of the display limit, but it does have USB4.

I see. Thank you. I thought Thunderbolt 3 is MiniDisplayPort.

By the way, can I convert the MiniDisplayPort Thunderbolt port on an old MacBook Air into a USB 3.2 gen 2 host port to connect an M.2 NVMe enclosre?