Comcast Corporation[note 1] is an American global mass media and telecommunications conglomerate that is the largest broadcasting and cable television company in the world by revenue. It is the second-largest pay-TV company after the AT&T-DirecTV acquisition, largest cable TV company and largest home Internet service provider in the United States, and the nations third-largest home telephone service provider. Comcast services U.S. residential and commercial customers in 40 states and in the District of Columbia. The companys headquarters are located in Philadelphia, Pennsylvania. As the owner of the international media company NBCUniversal since 2011, Comcast is a producer of feature films and television programs intended for theatrical exhibition and over-the-air and cable television broadcast.