A natural monopolies are an industry that runs best when one firm produces all the output.
Step-by-step explanation:
Natural monopoly existence might be due powerful economic factors influencing a specific industry. It usually comes into existence when industries are in need of some unique products or technology.
It also arises when a company understands its monopoly and rises accordingly to dominate the entire industry or when a single company is able to meet all the demands for that unique goods or service in the market. Example for this is tap water.