Twitter is an online social networking and micro blogging service that enables users to send and read short 140- character messages called "tweets". Registered users can read and post tweets. But unregistered users can only read them. Users may subscribe to tweets from other people. This is called following, and subscribers are known as followers.
Celebrities, politicians, film stars, models have verified accounts where they tweets and also upload pictures and their fans follow their tweets and get to know what they are upto. Twitter has mobile apps for iPhone, iPad, Android, Windows Phone etc.
I love Twitter and more than that I love tweeting. Also I follow my favorite star and read their tweets.