Monopoly vs Perfect Competition

Perfect Competition

In a perfectly competitive market, all firms sell undifferentiated products.
No single firm has market power, so they must accept the market price.
If there are profits to be made, new firms will enter the market, which drives prices down and eliminates the profits.
In the long run, no company in a perfectly competitive market makes an economic profit.

A monopoly owns its market and can set its own prices.
It produces at a quantity and price that maximizes its profits.
A good monopoly is a company that is so good at what it does that no other company can offer a close substitute.