Tell me whether these are names of movie directors or authors: Quentin Tarantino, Martin Scorsese, Christopher Nolan, Ernest Hemingway, Stephen King, J.K. Rowling

Quentin Tarantino is an American film director known for directing Pulp Fiction, Inglorious Basterds and Kill Bill.
Martin Scorsese is an American film director known for directing Goodfellas, Taxi Driver and The Wolf of Wall Street.
Christopher Nolan is a British-American film director known for directing The Dark Knight, Inception and Interstellar.
Ernest Hemingway is an American author known best known for writing For Whom the Bell Tolls and The Old Man and the Sea.
Stephen King is an American author known for writing It, The Shining and Misery.
J.K. Rowling is a British author known for writing the Harry Potter fantasy series.