Ah, but Debian is a different beast. They use a fixed-point release model, and barring urgent security updates, nothing ever changes anymore once you’ve installed the system. And then usually ─ not always but usually ─ if you want to go to a newer release, you have to reinstall.
Manjaro isn’t like that. The idea is that you install the system only once, and then you keep it updated. You will be notified of pending updates by way of an icon in the system tray, but I also advise everyone to subscribe to notifications here on the forum for the #announcements:stable-updates category.
As I said, Manjaro is a curated rolling release, which means that updates are generally bundled together ─ urgent security fixes or urgent bug fixes being the exception ─ and will appear on average twice a month. Each time, @philm will post an announcement about that to the #announcements:stable-updates category, with the changes and possible gotchas to look out for (along with their fixes).