A cartel differs from a monopoly in that

A cartel is a group of organization or people making the same product and fixing the price and the quantity of the production. They split the profit among themselves. This is also a kind of monopoly. It differs from monopoly in one sense and that is a monopoly business is run by a single individual. The profit is taken by him alone. The amount of profit in a cartel is less than that in a monopoly. Different people believe in different concept of business.