Applies to: OneNote for Windows 10 OneNote 2016 OneNote 2013 OneNote 2010 OneNote for Mac OneNote for the web.
In contrast with other Microsoft Office applications, OneNote has no Save command since physically saving your work here is unnecessary.
OneNote instantly and regularly logs and saves all your actions — including typing, editing, formatting, organising, searching, and sharing your notes. You can also safely leave OneNote whenever you want without initially exiting your notebooks or directly saving any of your work. OneNote saves and restores everything by default.
Don’t believe it? Test it for yourself. Visit any page in your notebook, write some text, and then immediately close OneNote. Launch it again and you’ll notice the previous page you were on — packed with the latest text you entered.