Sometimes after a really good movie, the audience breaks out in applause when the credits roll. This practice initially seems pretty pointless; afterall, the producers, screenwriters, and director(s) are not there to hear your applause.
The true purpose of this applause, however, is for moviegoers to tell each other, anonymously, how much they enjoyed the movie. It usually only takes a small group of people in the theater who really liked the movie to start applauding, and everyone else will as well.
Nothing beats really liking a movie and hearing the theater break into applause as the credits roll. It is satisfying to know you are not the only one that was moved by the film. Of course, if a film consistently gets applause in movie theaters around the world, the people who were responsible for its creation will likely hear about it and be grateful.