This Podcast explains the definition of market competition. The video also describes its types and impact on the common buyer.     

Do you ever hear that any company besides Apple is selling iOS-based devices? Surely never because the company holds a monopoly in the market in its business domain.    

 A monopoly is harmful to the common buyer but it is beneficial for the company as it holds the sole ownership of that product in the market. Monopolistic competition is slightly different than monopoly as it allows a few other companies to run the same product.   

Oligopoly allows healthy competition between different companies to run different products under their brand endorsement. What is the perfect market competition? The video explains the theory of perfect competition.     

So whether you are a buyer or a business person, all these types of markets exist around you in some way.