wordpress.org/gutenberg ::test the editor and all features
https://wordpress.org/gutenberg/
Say Hello to the New Editor
It’s a whole new way to use WordPress. Try it right here!
We call the new editor Gutenberg. The entire editing experience has been rebuilt for media rich pages and posts. Experience the flexibility that blocks will bring, whether you are building your first site, or write code for a living.
Dig in deeper - and learn alot :: head over https://wordpress.org/gutenberg/