In the United States, assistance dogs fall into two broad categories: service dogs and facility dogs.[12] Service dogs are defined by the Americans with Disabilities Act as dogs that are individually trained to do work or perform tasks for people with disabilities. State and local governments, businesses, and nonprofit organizations that serve the public generally must allow service animals to accompany people with disabilities in all areas of the facility where the public is normally allowed to go.[13] Facility dogs are used by working professionals to aid multiple people.[14]