Side Note opens in a small window.
Side Note is like a computer sticky note. You can have it open in a small window on-screen to note small details or comments as you think of them. The great thing is that these notes are saved in the Side Note section of your normal OneNote notebook.
You can start Side Note directly from an icon in the system tray on the taskbar . The Side Note section will be the open section in OneNote and the window smaller than normal (similar to the picture on the left). If you expand the window, you'll be back in OneNote, as you've seen it before.
You can have a regular OneNote window and Side Note open at the same time.
Just like the rest of OneNote, when you close Side Note your notes will be saved, and when you reopen it will take you back to the last page you worked on.
Note The Side Note section won't appear in OneNote until you start Side Note for the first time.