The Notebook is a 2004 movie production based on the novel by Nicholas Sparks, published in 1996.
The movie begins with an elderly woman at a retirement home who is being read a story by a man named Duke. The story is of a young country boy named Noah Calhoun and heiress Allie Hamilton. After Noah and Allie spend a summer together, Allie's parents decide this boy is not in the best interest of her future, and decide to leave town a week early. During the next year, Allie's parent fail to pass on the 365 letters Noah has written, while Allie has met a soldier whom she eventually becomes engaged to.
In the end, it's Allie who has to choose who she will end up with - Lon, her fiance who is everything society thinks her husband should be, or Noah, the one she feels she should be with.
It's later revealed that Allie is the old woman whom the story is being read to, but because she suffers from dementia, she cannot remember this story of her past with Noah.