1- Do more inside your inbox
You can now see and click attachements (e.g. photos and files) without having to open the email in which they were embedded. You ‘can also hover over messages (you don’t have to click into them) to do things like RSVP to a meeting invite, archive an email thread or snooze an email until the time is right.’
2- Integrtation with G Suite Apps
The new redesigned Gmail is integrated with more G Suite apps so you can work seamlessly across different platforms. Using the side panel on the right side of your inbox you will be able to quickly record notes in Google Keep, create and manage to-dos and tasks in Google Tasks (new app), and create and edit your Calendar invites. You can also use this panel to access the add-ons you use with your Gmail.
3- Smart reply and Nudging
As is the case with Gmail mobile, Gmail on the web is now supporting Smart Reply allowing you reply to messages faster. Gamil uses Articificial Intelligence to suggest contextual short replies you can use in your replies. Gmail will also ‘nudge’ you to remind you of important emails you need to attend to. And when a riskly email comes through, the new Gmail features a red alert warning.
4- Confidential mode
Check out this post for more details on these new features.