Twitter is the second most popular social network in the world. It was launched in 2006 and has around 310,000,000 estimated unique monthly visitors today.

The concept of Twitter is allowing users to send and read short 140-character messages called "tweets". Twitter has been called "The SMS of the Internet".

Founder Dorsey has explained the origin of the "Twitter" title:

...we came across the word 'twitter', and it was just perfect. The definition was 'a short burst of inconsequential information,' and 'chirps from birds'. And that's exactly what the product was.