Peppers or capsicums can be split into two distinct groups, the bell or sweet peppers and the chilli peppers, they are not related to the many other plants called pepper. With sweet peppers the green ones are usually the unripe pepper which ripens to shades of yellow or red depending on variety and ocassionally other colours. Chilli peppers, including Jalapenos and cayenne, contain a chemical called capsaicin which provides their heat! Growing conditions are similar to Tomatoes and they are happy growing alongside them, being smaller plants they are also happy grown in pots.