Twitter is an online social networking service that enables users to send, or ‘tweet’, 140-character messages, or ‘tweets’.

Users must register to post tweets, though unregistered users can read tweets without having to sign up. Users can access the service via desktop, SMS or mobile device app.

Users can subscribe to other users’ tweets, known as ‘following’, with subscribers known as ‘followers’. Users can retweet other users’ tweets, or quote tweets and add a message of their own.

Do you know which famous Larry Twitter’s famous blue bird is named after?

Users can group posts by topic or type by the use of hashtags, which are words or phrases preceded by #. Users can also create lists – a feature added in 2009 which lets users follow ad hoc lists of authors instead of individual authors.

One of the most-visited websites on the Internet, as of March 2016 Twitter was reported to have over 310 million monthly active users. Its blue bird logo has become synonymous with the service, with a 2012 omission from Twitter’s creative director revealing that the bird was called Larry and named after Larry Bird of the NBA’s Boston Celtics.