What is "sliding doors"

n. (sliding door English)

Sliding Doors is a 1998 British-American romantic comedy-drama film written and directed by Peter Howitt and starring Gwyneth Paltrow and John Hannah, while also featuring John Lynch, Jeanne Tripplehorn and Virginia McKenna. The film alternates between two parallel universes, based on the two paths the central character's life could take depending on whether or not she catches a train, and causing different outcomes in her life.