Where to find them
The bell in the header shows your latest unread notifications. All notifications lists everything grouped by day, with Mark all as read and Delete read.
What you are notified about
Status changes
For example when your note is published.
Comments and replies
New comments on your content, replies to you, votes on your comments.
Milestones
Views, votes, saves, solvers, comments, reputation levels, streaks.
Similar notifications are grouped while unread ("3 people upvoted your note"), so the list stays short.
E-mail settings
In Settings choose which notifications are also sent by e-mail: status changes, milestones, messages and comments.
