Story submission is part of social bookmarking from what I understand. There are two types of bookmarking 1. you submit the link of the article with title and description of the article. 2. you submit the link within your site or inner page of your site using your anchor text.
why do you think extra. there are many optons as directory submission, article submission, blogging, blog comments and use yahoo answer & Google group for discussion.
Both are different, social bookmarking is kinda submitting a link, without description. and story marking is kinda submitting summarized article, with the link.
hi, go onto actual websites or yahoo answers & you will get a better idea of exactly what the difference is.