What does it mean?
Filter Resonance emphasizes the area near cutoff; power-amp Resonance shapes low-frequency character. Neither is identical to physical acoustic feedback.
ExampleHigh Resonance in a wah or filter can raise the peak.
How the meaning changes between controls
Filter
Emphasis near cutoff, according to the filter's design.
Power Amp
Low-frequency or feedback-like response voicing in the power-amp model.