National Park Service Rangers are among the uniformed employees charged with protecting and preserving areas set aside in the National Park System by the United States Congress and/or the President of the United States. While all employees of the agency contribute to the National Park Service mission of preserving unimpaired the natural and cultural resources set aside by the American people for future generations, the term Park Ranger is traditionally used to describe all National Park Service employees who wear the uniform. Broadly speaking, all National Park Service rangers promote stewardship of the resources in their care - either voluntary stewardship via resource interpretation, or compliance with statute or regulation through law enforcement. These comprise the two main disciplines of the ranger profession in the National Park Service.