Explain how the inertia of an object is related to the object's mass

Inertia is a principle of motion that means a mass will keep doing what it is doing unless as equal and opposite force (push or pull) acts on it. This is related to mass as if you were to take 2 masses one big and one small and apply that same amount of force the smaller mass would have more inertia compared to the larger mass,   F= ma.