Shared Object is a new features of Flash MX. It is a contraption designed to allow local storage of data required by a user on that user's system. This is stored like a cookie. It can be used on a site to know if a user has already visited your site so that he may automatically skip the introduction. This can be disabled on the client side and has a code to check if its enabled on a user's system. The tutorial teaches the entire set of applications and also how to write good code so as to create and retrieve them when desired.