Social bookmarking is a method for Internet users to store, organize, search, and manage bookmarks of web pages on the Internet with the help of metadata.

In a social bookmarking system, users save links to web pages that they want to remember and/or share. These bookmarks are usually public, and can be saved privately, shared only with specified people or groups, shared only inside certain networks, or another combination of public and private domains. The allowed people can usually view these bookmarks chronologically, by category or tags, or via a search engine.

Most social bookmark services encourage users to organize their bookmarks with informal tags instead of the traditional browser-based system of folders, although some services feature categories/folders or a combination of folders and tags. They also enable viewing bookmarks associated with a chosen tag, and include information about the number of users who have bookmarked them. Some social bookmarking services also draw inferences from the relationship of tags to create clusters of tags or bookmarks.

Many social bookmarking services provide web feeds for their lists of bookmarks, including lists organized by tags. This allows subscribers to become aware of new bookmarks as they are saved, shared, and tagged by other users.

As these services have matured and grown more popular, they have added extra features such as ratings and comments on bookmarks, the ability to import and export bookmarks from browsers, emailing of bookmarks, web annotation, and groups or other social network features.

Digg is a website made for people to discover and share content from anywhere on the Internet, by submitting links and stories, and voting and commenting on submitted links and stories, in a social and democratic spirit. Voting stories up and down is the site's cornerstone function, respectively called digging and burying. Many stories get submitted every day, but only the most dugg stories appear on the front page.

Digg's popularity has prompted the creation of other social networking sites with a story submission and voting system.

StumbleUpon is an internet community that allows its users to discover and rate Web pages, photos, and videos. It is a recommendation system which uses peer and social-networking principles.

Web pages are presented when the user clicks the "Stumble!" button on the browser's toolbar. StumbleUpon chooses which Web page to display based on the user's ratings of previous pages, ratings by his/her friends, and by the ratings of users with similar interests. Users can rate, or choose not to rate, any Web page with a thumbs up or thumbs down, and clicking the Stumble button resembles "channel-surfing" the Web. There is also one-click blogging built in as well.

Yahoo! Buzz is a community-based news article website, much like Digg, that combines the features of social bookmarking and syndication through a user interface that allows editorial control. Users can be allowed to publish their own news stories, and link to their own or another person's site that links to a full story of the information, therefore driving traffic to that person's website and creating a larger market for sites that research and publish their own news articles and stories, such as CNN or smaller, privately owned websites.

Buzz, also like Digg, promotes the news stories that have been the most buzzed by users and displays them to the visitors of the website on the main page.

Buzz was created as a direct competitor to Digg. Yahoo! created the service in hopes that it would drive larger traffic to their site and would give them an advantage over larger online media companies such as Google or MSN, which are Yahoo!'s largest competitors in terms of search engines that provide services and web features to its customers.

Reddit (also reddit) is a social news website on which users can post links to content on the web. Other users may then vote the posted links up or down, causing them to appear more or less prominently on the Reddit home page.

The site has discussion areas in which users may discuss the posted links and vote for or against others' comments. When there are enough votes against a given comment, it will not be displayed by default, although a reader can display it through a link or preference. Users who submit articles which other users like and subsequently "vote up" receive "karma" points as a reward for submitting interesting articles.

The Reddit logo changes for various holidays and often for no reason, paying homage to Star Wars, classic video games, and geek culture in general. It often changes in response to major discussion subjects within the site or major news stories.

Although Reddit is not moderated by its owners, the Reddit developers have built a system to aid with curtailing spam, which works based on the "reports" of users.

Delicious (formerly del.icio.us, pronounced "delicious") is a social bookmarking web service for storing, sharing, and discovering web bookmarks. The site was founded by Joshua Schachter in late 2003 and acquired by Yahoo! in 2005. It has more than five million users and 150 million bookmarked URLs.

Squidoo is a network of user-generated lenses --single pages that highlight one person's point of view, recommendations, or expertise. Lenses can be about anything, such as ideas, people or places, hobbies and sports, pets or products, philosophy, and politics. Lenses aren't primarily intended to hold content; more emphasis is placed on recommending and then pointing to content on the web. Annotation and organization and personalization delivers context and meaning.

Users who create lenses are called lensmasters. A lensmaster uses the tools available online to provide links, feeds, abstracts, and lists to users who are trying to make sense of a topic. For example, a single lens could point to Flickr photos, Google maps, blogs, eBay auctions, YouTube videos, and other links. Lensmasters are encouraged to promote personal agendas, expertise, causes, products, and opinions. Squidoo has a Top 100 list by topic, by rank, by group and for Giant lenses. There are about 22 different topics like Health & Medicine, Food & Cooking, Business and many more.

Mixx is a user-driven social media web site that serves to help users submit or find content by peers based on interest and location. It combines social networking and bookmarking with web syndication, blogging and personalization tools.

Propeller, previously known as Netscape.com, is a social news aggregator operated by AOL-Netscape. It is similar to Digg; users can vote for which stories are to be included on the front page and may comment on them as well.

Propeller was hosted on the Netscape.com domain from June 2006 to September 2007 when it was replaced by the AOL Netscape generic portal.