Right Way to Use Module

Question

I wonder what is the right way to use modules. I mean I used them to stock some codes but I have the feeling that modules are intended more to be embed in a class than to be a box that stock code being called directly in a script. So the only right way to stock code is in a class and in modules intended to be extended or included in classes. Am I right ? Little confused..

ps: So rake tasks is not the right way to stock logic codes, rake tasks are only intended to call methods on classes which actually does something. Is it right ?