what is notification bubbles in developer option?

Bhai..go through this article, it will clear your all doubts regarding this notification bubbles..

https://www.google.com/amp/s/www.theandroidsoul.com/how-to-use-bubbles-on-android-10/amp/

Bhai..ye bulbule ki taraha notification show karega but only for compatible apps..

https://www.androidpolice.com/2019/05/10/notification-bubbles-will-be-hidden-in-android-qs-developer-options/?amp

https://www.google.com/amp/s/www.cnet.com/google-amp/news/7-best-android-10-features-how-to-use-them/

Bubbles are built into the Notification system. They float on top of other app content and follow the user wherever they go.

When the device is locked or the always-on-display is active, bubbles appear just as a notification normally would.

Don't know if you use facebook messenger but they have this feature to show new message notification.

Good to see responses for his doubts clarified.