I really like it when authors of children's books remember that details of how things work are fascinating to children. Gail Gibbons is definitely one of those authors. Her book is filled with very simple illustrations and text about trains, but the various parts of the trains are labeled and the text explains things like how the trains link together and the differences between gondola cars, hopper cars, boxcars and tank cars.The back page contains a chart of signs and signals relating to trains. Appropriate for preschool or kindergarten age children.