A Twitter essay is content supporting a particular thesis or viewpoint that is written through sequential and usually numbered tweets.
Twitter essays are created on the microblogging platform or an associated application. Tweets that form the essay are written individually but the accumulated tweets may be assembled on a site such as Tumblr or Storify. Because Twitter essays are published as separate tweets, they can be collaborative works, either by design or as a result of the format. As each tweet is published, it reaches the writer's social network. As a result, an essay's direction and focus -- and even the central argument -- may change as a result of input from replies.
The brief nature of tweets (optimally about 120 characters, to allow for retweets and perhaps comments) means that they tend to be concise. Each tweet must also be at least somewhat coherent on its own. Taken together, these constraints mean that a Twitter essay is not likely to have the flow of a traditional essay. In a Twitter essay collated in The Globe and Mail, Jeet Heer -- who popularized the form -- commented that a Twitter essay is not so much an argument as the skeleton of an argument.