Both “dated” and “outdated” can be used to describe things that are out of date, but the difference is that “dated” usually refers to things that are no longer in fashion, whereas “outdated” refers things that are not useful any more. For example,
outdated information = information that is not up-to-date
outdated software = software that has not been updated dated design = design that is no longer fashionable
dated kitchen = old-fashioned kitchen
dated decor = house decoration that does not look modern
I hope the examples make the difference clear. Dated things are usually perfectly functional and usable; they are just not considered modern enough. Outdated things are in some way no longer usable or suitable for the purpose they were made for; they are obsolete.