Twitter the microblogging and social network website was founded by Jack Dorsey in July 2006 after a brainstorming session with co-workers at Odeo, a podcast company.
It is one of the most popular social networks websites at the moment and by 2011 it was estimated that it had more than 300 million users worldwide.
It was inspired by the photography social network Flickr and by the 5 characters code of the american SMS.
Twitter is sometimes known as the 'SMS' of the internet.