Notifications - how do they work?

Hey, guys! Hope you are doing great here :)

I haven't been on these forums for a quite a while, and I've heard that notifications have been finally added.

Can anyone shortly explain to me how they work? Do you get notified via e-mail? Or on the web-site only? Do you get notifications for your own topics, or for any answers in any topics / chosen topics?

Thanks in advance!