Social bookmarking allows users to save, organize, and share bookmarks to web pages with others. Users can create accounts on social bookmarking websites to add bookmarks with tags. These bookmarks are usually public and can be searched and viewed by category or tags. Social bookmarking has advantages like enriching knowledge through shared bookmarks, but also disadvantages like potential errors from ambiguous tags. Popular social bookmarking sites include Delicious, Digg, Reddit, and StumbleUpon.