Law of multiple proportions

I don't understand how the law of multiple proportions work and the definitions online don't help. Can someone explain how it works with an example please?

It simply means that many elements can combine in more than one ratio.

H and O: H2O (water) H2O2 (Hydrogen Peroxide)

C and O CO2 (carbon Dioxide) CO (Carbon Monoxide) C3O2 (Carbon Suboxide)

Ag and F Ag2F (Silver Subfluoride) AgF (Silver Fluoride) AgF2 (Silver Difluoride)