Hello, antonia
in my book, 1) "red pepper" is a small, thin pepper, and VERY hot. Pimento? see:
http://images.google.fr/images?q=piment&hl=fr
2) then you have your usual pepper, which can be green, yellow or red, that you can eat in salads, on pizzas, or stuffed with ground meat, rice, ... see
http://images.google.fr/images?hl=fr&lr=&q=poivron
3) Finally, the pepper tree gives "beans" or "bays"?, that, when ground, are used along with salt during meals etc... That pepper can be white, black, pink, even grey if I'm not wrong. see:
http://images.google.fr/images?q=grains+de+poivre&hl=fr
Sorry for the French, but in English, it seems English has no different name for 1) & 2), but in French we make the difference.
Has it helped?