Market fucntion and the mechanismis

competition and number of substitute products, If there are many competition in the market place, then the price will be bring down.

I think you can answer this question by reading your economics textbook=factors affecting demand and supply
I'm sure you can find the answer

You have to go way back into the assumptions of the different forms of market:

1. perfect competition - homogeneous goods, suppliers (producers) as price-takers, perfect elasticity, etc
I.e. eqm p determined by market demand and supply

2. monopoly - heterogeneous goods, suppliers has perfect power, prices inelasticity, etc.
eqm p determined by monopolist's profit maximization condition

3. monopolistic competition - similar but not exactly the same goods, suppliers has SOME market power,
eqm p determined by the zero economic profit condition. when there is no further entry or exit of firms feasible within the industry.

Hope this helps!