A public utility is a company that maintains the infrastructure for a public service. Public utilities often involve natural monopolies, and as a result are often government monopolies, or (if privately owned) treated as specially regulated sectors.
In poorer developing countries, public utilities are often limited to wealthier parts of major cities, as used to be the case in developed countries in the nineteenth century.
Examples of utilities are:
Developments in technology have eroded some of the monopoly aspects of traditional public utilities. For instance, electricity generation, electricity retailing, telecommunication and postal services have become competitive in some countries and the trend towards liberalization, deregulation and privatization of public utilities is growing.