Why does painting metallic objects that contain iron help prevent the formation of rust?

OF COURSE IT DOES???? DID YOU SEE SEE A BRIDGE that was all rusty and never painted??? Geeeez don't people learn anything in school now-a-days???Why does painting metallic objects that contain iron help prevent the formation of rust?
Rusting is oxidation of iron and requires water and oxygen to proceed.


paint restricts or cuts off water and oxygen from the surface of iron thus preventing oxidation or at least retards the process from completion.


thnks