Classic Hollywood style is a style of filming and producing in that was most prominent in Hollywood in the 1930's and 1940's. The two most affluential film makers of classic Hollywood style were the companies, Metro Goldwyn Mayer and Warner Brothers/Bros. They were both very successful but very different.
Metro Goldwyn Mayer or MGM made big, elaborate films. They had money being poured into them by investors and any other means they could manage. They were big budget films. They used famous actors and stars in there movies that the public knew and loved. MGM also pioneered new types of more expensive film stock like technicolor. They would have sets and props built especially for there films. However because of the expense that went into making there films they made very few films per annum.

Warner Bros made films that had less expenses to them, but they made a lot of them. They could churn out plenty of films per year. They used sets and props and costumes repeatedly, even in separate films. They mostly made detective and crime movies. Warner Bros also used the same actors in nearly all of there films because they had there actors on contract. This meant that the actor would make as many films as his/her contract stated and get paid the amount that was also stated on the contract. Most of Warner Bros classic Hollywood films were filmed in Black and White as opposed to MGM's colour films.