Here’s an overview of my latest OneNote article:
Microsoft OneNote has garnered a large population of mostly PC-centric users since its first release in 2003. Of OneNote's competitors, the most prominent is Evernote, which addresses some of the same requirements, but from a different starting point. In this article Peter O'Kelly introduces Evernote, compares OneNote and Evernote, and provides some guidance on how you might want to consider using Evernote and OneNote together, if you routinely use non-Windows devices.
A couple conceptual model diagrams, to give you a sense of the differences between Evernote and OneNote:
See the article link below for more details, screen shots, etc.