How is aperture measured? what do the measurements mean?

Aperture is measured in F-stops, in which the f-stops is the amount of light allowed to pass through the aperture, which simply put means that the smaller the aperture, the higher the f-stops. What it does is reduce the amount of light that reaches the film, so the higher the f-stops, the less light reaches the film.

Ithink the answer is d i hope it my friend message me if i’m wrong and i’ll change my answer and fix it for you