OneNote is a free form notepad that enables a user to copy and paste text, images, videos, and emails onto a page and save the page in a notebook within a folder.
Here is a screenshot of one page of information in my filing cabinet. At the top of the application window you see a ribbon toolbar, currently the HOME tab of the toolbar is selected. Each tab provides a toolbar with specific features that are quick to find and intuitive for new users. Just below the ribbon toolbar, the window is divided into 3 sections which are (from left to right) Notebooks, Folders, and Pages. The Notebooks section will list all of your notebooks.
OneNote is a Digital Filing Cabinet
OneNote Has a Powerful Search Feature

Here is a 30 second video prepared by Microsoft that demonstrates the power of OneNote.