Monopoly: A single seller-large no of buyers, There is no alternate product.
Ex : Multichoice with DSTV
Duopoly: Two sellers shares the maximum market share (Ex: Pepsico and Coco-cola)
Monopolistic: Exactly Opposite to monopoly. no of sellers produces a similar product. (Aromat)
Perfect competition: If large no of buyers, and large no of sellers present in a particular market area then it is called as perfect competition. (Mobile operators- MTN, 8ta, Cell C, Vodacom and Virgin Moble )
Oligopoly: it is a market situation where the sellers command the over all industry to increse the product price ect. in oligopoly situatiuon the sellers produces an identical product like same features with same inputs. (MTN and Vodacom)