The former is wireless charging, and the latter is a wired fast charging protocol for convenient travel and compatibility with more devices.
Qi is the \"Wireless charging\" standard launched by the Wireless Power Consortium (WPC), a standardization organization that promotes wireless charging technology, which has two characteristics of convenience and versatility.
pd fast charge is a fast charge specification developed by USB-IF organization, and is one of the mainstream fast charge protocols at present.
USB-PD is a fast charging specification developed by the USB-IF organization, and is one of the mainstream fast charging protocols. The USB-PD fast charging protocol is output by the Type-C interface, but it cannot be said that the Type-C interface must support the USB-PD protocol fast charging.
q I fast charge is q I fast charge, and pd fast charge is pd fast charge.