In a monopolistic market, the many different companies combined have no specific control over the business at hand as far as the market price. They would be considered to be a monopoly of sorts. they are actually considered an imperfect competiton, being the exact opposite to the next question regarding perfect competition.
Within a perfectly competitive market, all of the firms involved have a market share or slice of the pie as some may see it. All parties involved have the same information on the product that they are selling at hand. The pricing is created by the firms but every company involved has the control of their market value.
