There are several kinds of mascara to choose from. Cake mascara is popular with models, because it lasts a long time.
There is waterproof mascara, which is fine if you swim or cry a lot; it stays intact on your lashes and will only come off with an eye makeup remover specifically made for this type of mascara. Regular mascara or water-soluble mascara will run if you tear and is easily removed with plain old water. Yet another kind of mascara has little fibers in it to make your lashes look thicker.