Floating windows
Several windows at once
You can keep as many notes open as windows as you like. Each one is independent.
Each note gets at most one window. Open the same note again and the existing window comes forward instead of a second one appearing. Different notes sit side by side independently, each with its own position and size.
Telling them apart by colour
A floating window carries the colour of its note. With three or four windows open you can tell which is which by the tint, without reading the title. Assigning colours is covered under Note colours.
Closing them
Each window closes at the left of its title bar or with ⌘W. Closing a window deletes nothing; the note stays in the library.