Social media are technologies and platforms that enable social interactions (e.g., conversations, discussions, content sharing) between multiple users on the web and/or mobile devices. Social media include social networking sites such as Facebook, LinkedIn, and Twitter; blogs and wikis, such as The Huffington Post and Wikipedia; and photo and video sharing sites, such Flickr and YouTube.
Some types of social media sites first took off among the general public, and similar sites tailored to scientists were developed later. Therefore some scientists and scientific institutions have presence both on general social media sites and sites specifically for scientists.
Like other websites and web-based businesses, social media sites come and go. For example, Elsevier launched a scientific social network called 2collab in 2007, but this was discontinued in 2011. Similarly, Nature Publishing Group launched a social bookmarking site called Connotea in 2004, but this will be discontinued in March 2013.
The blog ProfHacker, from the Chronicle of Higher Education, often contains posts about innovations in the development and use of social media in education.