Almost every ClassNori feature applies to “the students selected right now”. The target follows from the selection automatically, so learning this one rule prevents most mistakes.

Selection	What happens when you press a ribbon button
Nobody selected	Applies to every student in the tab you are viewing (the whole class on the All tab, that team on a team tab).
One student selected	Applies to that one student only.
Several selected	Applies to every selected student.

Figure 3. How the selection decides the target

The current target is always shown in the target chip at the left of the status strip — for example “Target: All 28 students”, “Target: Group 1 — 7 students”, “Target: 3 selected (Kim Minjun and 2 more)”. The selection is kept when you move between team tabs, so if it includes students picked in another team the chip turns orange and tells you, as in “Target: 3 selected (2 in other groups)”. Check it once before pressing a feature that is hard to undo, such as lock or shut down. Clear the selection with ESC or by clicking an empty area.

The right-click menu behaves a little differently.

With nothing selected, right-clicking a card applies to that one machine (it is selected for you).
With several already selected, right-clicking a card inside the selection applies to all of them; right-clicking a card outside it applies to that one machine only.

Who a feature applies to — the selection rule (important)