A Public utility (often called a "utility") is an organization which manages and looks after the equipment and facilities used to provide a service. Often, they also use that equipment and facilities to provide the same service. Public utilities can be small groups based in a local community or large businesses owned by a government.
The word "utilities" can also mean the services provided by these companies. Examples are things like Gas, Water, Sewerage, Electricity, Television, and Telephone services. Cellphone and Internet services are also being included more often in this definition.