For a number of years now, users on Twitter have been using “threads”, which are basically a chain of consecutive tweets, used to tell a story or expand a train of thought. Each tweet after the first is a reply to the last.
Twitter has now added a new official function to make threads easier for users by adding a plus button to the composer. You can now build on your first tweet via the plus button, then publish the entire thread when done.
Threads are now more easily identifiable, as they are now labeled with “Show this thread”.
The update that includes the new thread functionality will be rolled out to the iOS, Android, and web client platforms in the coming weeks, so be sure to keep your apps updated.
Source: Twitter