Public works represent a significant portion of city operations, impacting budget, customer service, staffing, projects, and essential municipal functions. Donald C. Stone, founder of the American Public Works Association (APWA), defined public works as:

"The physical structures and facilities developed or acquired by public agencies to house governmental functions and provide water, power, waste disposal, transportation, and similar services.

In essence, public works departments build, operate, and maintain infrastructure while providing services that benefit the public. The APWA has identified 145 functions related to public works, which can be grouped into eight broad categories:

1. Transportation covers streets, bridges, sidewalks, bike paths, airports, seaports, traffic control, and stormwater management. Public works is responsible for the design, construction, and maintenance of these facilities.
2. Sanitation includes collection of solid waste, brush, leaves, and bulky items. Cities, counties, or private entities may operate disposal facilities such as landfills, compost facilities, and incinerators. Many municipalities also manage recycling programs.
3. Utilities encompasses water, wastewater, gas, and electric services, and may include cable TV, internet, stormwater, and flood control. Utilities may be managed by public works or separate city departments, or operated by other governmental entities or private companies.
4. Buildings & Grounds involves the design, construction, maintenance, and management of public buildings and facilities, including urban forestry.
5. Municipal Engineering covers civil and environmental engineering tasks such as facility design, technical studies, construction inspection, and surveying. Larger departments may perform some engineering in-house, while complex projects are usually contracted.
6. Fleet Management involves procurement and maintenance of city-owned vehicles and equipment. Some departments manage only their own fleet, while others provide services to multiple departments. Outsourcing of maintenance is also common.
7. Management & Administration includes operations management, supervision, financial reporting, public relations, procurement, contract management, and related administrative functions.
8. Other Functions may include parks maintenance, cemetery operations, airport services, animal control, and dead animal pickup, among others.