A message film is like when your mom or dad tells you a story with a moral at the end. The movie has a story about characters and things that happen, but it also has a message or lesson it wants you to learn. Just like how your parents might tell you to be kind to others or to always tell the truth, message films have lessons they want to teach you about real-life issues.
Sometimes message films have a very specific focus, like bullying or the environment, and they use the story and characters to teach you about that topic. Other times, the message might be more general, like to be true to who you are or to never give up on your dreams.
These movies might use different techniques to get their message across, like having characters talk about it or showing things happening that are related to the message. The idea is to make you think and feel something about the topic so that you remember the lesson even after the movie is over.