What is Public Service?

Legal Definition
Public service is a service which is provided by government to people living within its jurisdiction, either directly (through the public sector) or by financing provision of services. The term is associated with a social consensus (usually expressed through democratic elections) that certain services should be available to all, regardless of income, physical ability and/or mental acuity. Even where public services are neither publicly provided nor publicly financed, for social and political reasons they are usually subject to regulation going beyond that applying to most economic sectors. Public policy when made in the public's interest and motivations can provide public services. Public service is also a course that can be studied at a college and/or university. Examples of public services are the fire brigade, police, air force, and paramedics.
-- Wikipedia
Legal Definition
A service that is provided by and or supported by a government or its agencies. An agency that provides a publice service for the government or on behalf of the government.
Legal Definition
A term applied in modern usage to the objects and enterprises of certain kinds of corporations, which specially serve the needs of the general public or conduce to the comfort and convenience of an entire community, such as railroads, gas, water, and electric light companies.
-- Black's Law Dictionary