Five years after it went public, the social media website Twitter now has over 200 million user accounts and is growing worldwide.
From businesses and celebrities to the average person on the street, it offers direct communication with thousands - even millions - of followers.
This year, the site saw a leap in usage during Japan's earthquake and tsunami in March, as well as during the ongoing uprisings in the Arab world, where protesters were able to communicate and organise without having to meet in real life.
Twitter's success is due in large part to its simplicity and versatility, as well as the ability its users have to determine its actual use.
Al Jazeera's Tarek Bazley reports.