Power Supply switching frequency - what?

I greet all the members of the forum.
I apologize if maybe I posted in the wrong section, but in fact, the purpose is to fix a power supply of a car audio amplifier, so it seems right.
I'd like to understand one thing.
When we speak of "oscillating frequency of a switching power supply" do we speak of the frequency that is read on the gate of the mosfets, or of the triangular one (sawtooth) present on pin 5 of the TL494 or pin 6 of SG2525?