What does social media mean?
Social Media is a term used to identify user driven media as opposed to traditional media like TV, newspapers and magazines.
In traditional media, only individuals with approved credentials or "good" contacts, have an opportunity to contribute, but with social media, anyone with an internet connection can voice their opinion to the world.
Twitter, a major social media site, has changed the way news travels. Eye-witness accounts often hit the Twitter stream long before traditional news can get their reports to the airwaves.
Social Media has gone mainstream and is now recognized by all major traditional media outlets.