A firefighter is a first responder trained in public safety and emergency response such as firefighting, primarily to control and extinguish fires and respond to emergencies such as hazardous material incidents, medical emergencies, road traffic collisions and other emergencies that threaten life, property and the environment, as well as to rescue persons from confinement or dangerous situations and preserve evidence. The fire department, also known in some countries as the fire brigade or fire service, is one of the three main emergency services. From urban areas to aboard ships, firefighters have become ubiquitous around the world. Firefighters work closely with other emergency response agencies such as the police and emergency medical service. A firefighter's role may overlap with both.