Black Pepper (Piper nigrum L.) of Piperaceae family, is a vine plant native of South India. It is mainly cultivated for its fruit, peppercorn: dark red when fully mature, it is usually harvested when still unripe, and is then cooked and dried to be used as a spice. More precisely, it is known as black pepper if unripe fruit are cooked and dried, and as green pepper unripe fruit are just dried. The ripe fruit seeds are known as white pepper.
Besides being much used in cooking as a spice, it is also used in traditional medicine, to treat constipation, indigestion, heart diseases and more.
Black Pepper spiciness is due to the alkaloid piperine, definitely different from the capsaicin, giving bell peppers their flavor.
Black Pepper can be sold both in grains or powdered. Famous recipes with Black Pepper are, for example, egg sauce and jugged hare.
Fun fact: Black pepper is the most traded spice in the world, and is among most common spices in European cuisines.