A natural monopoly is a monopoly in an industry in which high infrastructure costs and other barriers to entry relative to the size of the market give the largest supplier in an industry, often the first supplier in a market, an overwhelming advantage over potential competitors. Specifically, an industry is a natural monopoly if a single firm can supply the entire market at a lower long-run average cost than if multiple firms were to operate within it. In that case, it is very probable that a company (monopoly) or a minimal number of companies (oligopoly) will form, providing all or most of the relevant products and/or services.