A very popular online microblogging service; the maximum size of the messages that can be posted, referred to as tweets, is 280 characters. Originally developed as a short messaging service in 2006, it has expanded into a global web-based system for spreading news and opinion. As such it has benefited greatly from the emergence of the smartphone. In (2019) it had around 321 million active users.

https://twitter.com/ The Twitter website