Bell pepper, (Capsicum annuum), also called sweet pepper or capsicum, pepper cultivar in the nightshade family (Solanaceae), grown for its thick, mild fruits. Bell peppers are used in salads and in cooked dishes and are high in vitamin A and vitamin C. The large furrowed fruits are technically berries and can be green, red, yellow, or orange. Bell pepper plants are grown as annuals.
 
Uses 

Like the tomato, bell peppers are botanical fruits but culinary vegetables. Pieces of bell pepper are commonly used in garden salads and as toppings on pizza or cheesesteaks. There are many varieties of stuffed peppers prepared using hollowed or halved bell peppers. Bell peppers (and other cultivars of Capsicum annuum) may be used in the production of the spice paprika.
Bell peppers are 94% water, 5% carbohydrates, and negligible fat and protein (table). They are rich sources of vitamin C, containing 97% of the Daily Value (DV) in a 100 gram reference amount (table). Their vitamin B6 content is moderate (17% DV), with no other micronutrients present in significant amounts (table). Red bell peppers have approximately twice the vitamin C and eight times the vitamin A content than green bell peppers.
The bell pepper is the only member of the genus Capsicum that does not produce capsaicin, a lipophilic chemical that can cause a strong burning sensation when it comes in contact with mucous membranes. They are thus scored in the lowest level of the Scoville scale. This absence of capsaicin is due to a recessive form of a gene that eliminates the compound and, consequently, the "hot" taste usually associated with the rest of the genus Capsicum. This recessive gene is overwritten in the Mexibelle pepper, a hybrid variety of bell pepper that produces small amounts of capsaicin (and is thus mildly pungent). Sweet pepper cultivars produce non-pungent capsaicinoids.