Yes, 'The Vow' book is based on a true story. It often delves into real - life experiences and relationships that are then adapted into a narrative for the book.
It's likely about a real - life relationship. Maybe it details the experiences and promises (the 'vow') between two people in a relationship that actually occurred.
The Vow has roots in true events, but it's not a strictly 100% accurate portrayal. Filmmakers often blend reality with imagination to create a compelling story on the screen.