Well, I do bookmarks on my web browser, I use bookmarks while reading books but social bookmark would be like bookmarking on social networks. It is straight answer that I can give. Social bookmarking is done to promote your website and several people can see it. However, If there is any other kind of bookmarking that I am not aware of, I am sorry for that.
Social Bookmarking is a similar to bookmarks. Bookmarking we can add links or bookmarks to our favorite Web Pages and save them on our computers. But these links are limited to only our computers, we can’t access these links on another computer .Social Bookmarking Remove this problem. When a page is bookmarked within a social bookmarking setting, the bookmarks will be viewed across the web.
The differants from "social" and that is all! Social bookmarking and bookmarking is a powerful tool in promoting a website! That is why, this points use more in SEO! But, I think it dosen’matter)
Simply put, usually you say "bookmarking" when you bookmark a URL on your browsers, "social bookmark" when you do the same, although on websites where it is usually published so it's available to the public. The promotional aspect of social bookmarking is pretty obvious, but some allow you to restrict access to that bookmark, even setting it to private.
Social bookmarking is a tagging a website and saving it for later! so instead of saving them to your web browser, you are saving them to the web, just because your bookmarks are online, you can easily share them with your friends!
Bookmarking is a facility offered by 'bookmarking websites' so that you can store bookmarks of your favorite sites / pages on the web. These bookmarks are generally private and only accessible to you when you log in to your account on such bookmarking sites. Social bookmarking is the feature when you allow your bookmarks to be public - accessible either to your friends on the bookmarking site or to the general public. That's why only social bookmarking can offer the indirect benefit of getting backlinks from bookmarking sites.
I use this sometimes... during the process I noticed some of it are dead(404) and not working anymore... I got this thinking that it could happen to other and if I submit my site it would be a waste of time.