"Selma" the movie is a historical drama that focuses on the 1965 voting rights marches from Selma to Montgomery led by Martin Luther King Jr., while the book "Selma, Lord, Selma" is a work of historical fiction that tells the story of the marches through the eyes of a young girl named Sheyann Webb. The movie provides a cinematic dramatization of the events, while the book offers a more personalized and fictionalized account from the perspective of a child participant.