Warner Bros. Entertainment Inc. (previously incorporated as Warner Brothers Pictures, Inc. and colloquially known as Warner Bros. and Warner Bros. Pictures) is an American entertainment company that is a division of Time Warner and is headquartered in Burbank, California. It is one of the "Big Six" major American film studios. 

Warner Bros. is a member of the Motion Picture Association of America (MPAA). 

The company's name originated from the four founding Warner brothers (born "Wonskolaser" or "Wonsal" before Anglicization): Harry, Albert, Sam, and Jack Warner. They emigrated as young children with their parents to Canada from Krasnosielc which was located in the part of Congress Poland that had been subjugated to the Russian Empire following the eighteenth-century Partitions of Poland near present-day Ostrołęka. 

Jack, the youngest, was born in London, Ontario. The three elder brothers began in the movie theater business, having acquired a movie projector with which they showed films in the mining towns of Pennsylvania and Ohio. In the beginning, Sam and Albert Warner invested $150 to present "Life of an American Fireman" and "The Great Train Robbery". They opened their first theater, the Cascade, in New Castle, Pennsylvania, in 1903. 

When the original building was in danger of being demolished, the modern Warner Bros. called the current building owners, and arranged to save it. The owners noted people across the country had asked them to protect it for its historical significance.
How many founders are there?
 from the four founding Warner brothers