https://techcrunch.com/2020/03/04/twitter-starts-testing-its-own-version-of-stories-called-fleets-which-disappear-after-24-hours/

Twitter is testing its own version of Stories. The company announced today it will begin to trial a new sharing format called “Fleets,” starting in Brazil, which will let users post ephemeral content to its social network for the first time. Unlike Tweets, Twitter’s new Fleets can’t receive Likes, Replies or Retweets. And they’ll disappear entirely after 24 hours.

Fleets aren’t non-public, to be clear; they’re just a little less accessible. You could visit someone’s public Twitter profile and tap to view their Fleets even if you don’t follow them. But their Fleet won’t circulate Twitter’s network, show up in Search or Moments, and it can’t be embedded on an external website.