Which class of airspace is considered uncontrolled?

Class G airspace is considered uncontrolled because it does not have an air traffic control (ATC) service provided. Unlike controlled airspace classifications, such as Class A, B, and D, where ATC actively manages the traffic, Class G allows pilots more freedom to operate without the requirement to communicate with air traffic controllers. This airspace typically exists at lower altitudes and can extend from the surface to the base of controlled airspace, often being found in rural or less populated regions. Pilots flying in Class G must still adhere to visual flight rules (VFR) or instrument flight rules (IFR) as applicable, but they bear the primary responsibility for maintaining separation from other aircraft.