Twitter is a free on-line micro-blogging service: a social network based on tweets, short messages containing a maximum of 140 characters, allowing users to tell their followers what they are doing at any given moment, and allowing them to follow the activities of other users. The messages can be sent and received via the Twitter website or using mobile devices, and can be restricted to a user’s circle of friends or can be open access.
Twitter thus lowers the barriers for sending information on line, and is a much more interactive experience than other methods. Recently, the number of users has grown exponentially. According to Compete, Twitter became the third most used social network in February 2009, with 6 million visitors.
The talks established between users can be found and organised through hashtags or labels. Hashtags can be followed through twubs, a tool that allows you to access or create communities built around these tags.