New in Craft CMS 3.1
Project Config
One of the most exciting new features might be Project Config, which allows sections, fields and other settings to be kept in sync across multiple development environments without having to share the database.
Fittingly, other control panel settings can be set with new Environment Variables, so that less sensitive data needs to be stored in the database or Project Config.
New Config setting
Thanks to allowAdminChanges config settings, it is possible that no administrative changes can be made on the live server. Customers can change content, but updates, installation of plugins, etc., then goes only locally (as it should be).
Soft-Deletes
Soft Deletes allow content to be restored within 30 days.
As of Craft 3.1, Soft Deletes are widely supported. Deleting entries, categories, users, or other items is no longer a deletion. Still, they automatically get a discarded status, so they are put into a virtual recycle bin, where they could be restored within 30 days.Entries, categories, and users can even be restored directly from the control panel. For example, click on entries and the status button, which shows "All" by default, set the status to "Discarded". Then only the corresponding entries are displayed, and you can restore them.
Redesigned plugin store
The plugin store, which contains over 450 Craft plugins, has been completely redesigned. It is now possible to find plugins, view changelogs, or buy plugins and Craft Pro directly from the website.
Plugins can now have multiple editions so that you can provide packages for different project sizes. So a plugin as a regular and Pro version, for example. But still, plugins can be tested locally for free.