Monopoly and Perfect competition markets

Monopoly Marketing -
Monopoly marketing is when a company is an individual provider of a good or service within one industry. This automatically makes the company powerful enough to prevent competitors from entering the marketplace leading to considerably fewer choices for the consumers, higher prices & limited response to customer cares.
If the govt senses there is an unfair monopoly in play, it steps in and places anti-trust laws to penalize the company by imposing heavy fines or force the company to break up. These laws protect consumers and ensure that the marketplace remains open and competitive.
However, there are instances where the monopoly market is preferred. For example, there's only one Electric supply company serving consumers in a large area. If that wouldn't have been so, the neighborhood would have been overrun with utility poles and electric wires as the companies fight it out to sign up new customers. So to prevent a chaotic situation government allows companies like CESC to run their business in the whole of Howrah, West Bengal and WBSEDCL in the whole of Salt Lake, West Bengal.
But the government closely monitors and regulates the companies & controls the rates it can charge.

Perfect Competition:
Perfect competition is a theoretical market structure where competition is at its highest possible level. Stock exchanges and commodity markets approximate perfect competition. But perfect competition in a market is not feasible in real life. In hypothesis for perfect competition to exist the following criteria has to be met:
1. all firms sell an identical product (the product is a "commodity" or "homogeneous")
2. all firms are price takers (they cannot influence the market price of their product)
3. market share has no impact on price
4. buyers have complete or "perfect" information – in the past, present and future – about the product being sold and the prices charged by each firm; 5. resources such as labor are perfectly mobile; and firms can enter or exit the market without cost.
A great example of perfect competition would be - there are 3 fishermen who sell the same kind of fish for a 100 Rs. One day they realize they needed to gain extra profit so increased the price to 150 Rs. But the next day, a 4th fisherman enters the market and sells the same fish for 100 Rs and obviously, his sale was higher than the other 3. Eventually, due to perfect competition, the 3 fishermen had to lower their price to the same rate of Rs 100 as their product won't sell at an inflated price.