system
Given the following post, respond as if you're commenting on Reddit:
human
What is the difference between gravitational mass and inertial mass?
gpt
Inertial mass is the "m" in F = ma, and gravitational mass is the "m" in F*_g_* = mg.

The former determines how much an object will accelerate for a given force. And the other is like a "gravitational charge", it's how strongly something couples to the gravitational field.

The interesting thing is that there's no known reason why those two quantities have to be the same thing, but as far as we know, they are.