Peppers are the fruits of Capsicum annuum, a plant (or rather, a group of botanical varieties) belonging to the Solanaceae family.
Peppers are also an excellent source of beta carotene and other carotenoids; in general, the more red they are, the more beta-carotene and vitamin C they contain (a ripe red pepper can contain, for the same weight, up to 4/5 times more vitamin C than an orange).
The shrub of the peppers is erect, provided with a light hair and no more than 100-150cm high; the plant has green and shiny, lanceolate leaves, the flowers are white and grow just below or above the leaves (near the leaf axilla), respectively one per node. Peppers consume the fruit, or rather the berry; this, first green and then (after maturation) pigmented with yellow or red according to the variety, contains a placenta (white film) that binds some light, round and flattened seeds. For the uninitiated, just the placenta and the seeds contain the famous spicy active ingredient of peppers (more precisely peppers): capsicina.