With the new Gutenberg editor for WordPress (coming in 5.0), your content will be made up of blocks. Each paragraph, image, quote, heading (and a lot more) are all discrete pieces of information which Gutenberg calls blocks.
WordPress natively has the ability to schedule an entire post for a specific future date and time (which may or may not always be reliably adhered to, but that’s a different story). There are plugins that allow you to schedule when a post should be ‘unpublished’ – i.e. no longer publicly available.
However, what if you wanted only part of your post – say a paragraph or two – to go live (or stop being live) at a specific time and date? Technically possible with shortcodes, but that’s going to get ugly real fast. And, well, shortcodes are part of WordPress past. What about WordPress future?
This is where scheduled blocks comes in.