Social bookmarking is a web based service to share Internet bookmarks.
Social bookmarking sites are a popular way to store, classify, share and search links through the practice of folksonomy techniques on the Internet or Intranet.

What's with these icons that lead me to login screens?

These icons let social bookmarking site users flag web pages as interesting in one or two clicks. They're a trendy way to attract herds of visitors on web sites.

Why should I care about social bookmarking sites?

The main benefit of using a social bookmarking site is that they let you keep your bookmarks when you switch computers. These sites typically let you organize your bookmarks using keywords ("tags") rather than category trees. And users typically find tags more natural to use. These tags then let you to spread information to other users. Reciprocally, they let you discover information found by others via tag-specific RSS feeds. The resulting cooperative classifications are called folksonomies. Interpretation differences, gossip, lemmings with an agenda and spammers invariably ensure that folksonomies have a low signal to noise ratio.

How do I use social bookmarking sites?

It's super simple. Log into del.icio.us, Digg or Furl and click the relevant icon on web sites that you find interesting. There are of course many more social bookmarking sites and tools. But none of these really stand out.

   www.del.icio.us

   www.digg.com

   www.furl.net

History

The concept of shared online bookmarks dates back to April 1996 with the launch of itList.com. Within the next three years online bookmark services became competitive, with venture-backed companies like Backflip, Blink,[citation needed] Clip2, Hotlinks, Quiver, and others entering the market.

Functional overview

In a social bookmarking system, users store lists of Internet resources, which they find useful. These lists are either accessible to the public or a specific network, and other people with similar interests can view the links by category, tags, or even randomly. Some allow for privacy on a per-bookmark basis.

They also categorize their resources by the use of informally assigned, user-defined keywords or tags. Most social bookmarking services allow users to search for bookmarks which are associated with given "tags", and rank the resources by the number of users which have bookmarked them. Many social bookmarking services also have implemented algorithms to draw inferences from the tag keywords that are assigned to resources by examining the clustering of particular keywords, and the relation of keywords to one another.

Its increasing popularity and competition have extended the services to offer more than just sharing bookmarks, such as rating, commenting, the ability to import and export, add notes, reviews, email links, automatic notification, feed subscription, web annotation, create groups and social networks.

Automatic notification

Since the classification and ranking of resources is a continuously evolving process, many social bookmarking services allow users to subscribe to web feeds (RSS) based on tags, or collection of tag terms. This allows subscribers to become aware of new resources for a given topic, as they are noted, tagged, and classified by other users.

What are tags?

Tags are one-word descriptors that you can assign to your bookmarks on del.icio.us. They're a little bit like keywords but non-hierarchical. You can assign as many tags to a bookmark as you like and easily rename or delete them later. Tagging can be a lot easier and more flexible than fitting your information into preconceived categories or folders.