Compare Perfect Competition and Monopoly

A. Similarities

Perfect Competition Monopoly
Products
Perfectly compeitive firms produce 
homogeneous products.
Under pure monopoly there is
 only one firm producing a single product
Aim
Perfect competition aims to maximise profits  Monopoly aims to maximise profits

B. Differences

Numbers of Firms
There are many firms in perfect competition There is only one firm under monopoly
Influence on Market
Because there are so many firms operating under perfect competition, they are insignificant that they cannot influence the price The monopolist being the only firm in the 
 marketplace exerts complete control over
 the market
Entry and Exit
There is freedom of entry and exit under perfect compeititon   Under monopoly there is no freedom of entry
Profits
There is widespread knowledge of profits under perfect competition  Since there is only one firm in monopoly
 there is no necessity to disclose profits
Types of Profit
Because of the intensity of competition between perfectly competitive firms they earn Normal Profit  Because there is no competition within monopoly, the firm is able to sell its  product at a high price enabling it to earn Supernormal Profit