Evernote is a note taking tool that is accessible from your web browser, desktop client, or app. Beyond notes you can save many other types of content such as screenshots, web clippings, scans, pictures and emails.
Files in Evernote can be organized into individual "notebooks" . You can also use the tagging feature to organize your documents into categories. Evernote also indexes your content for searching, including handwritten notes. You can also set up smart searches based on specific tags, upload location, and date.
One Note (Microsoft) works similarly to Evernote and allows you to combine all your notes in one place and allows tagging.If you use other Microsoft products it integrates well with them. It allows you to share notes and notebooks with other OneNote users for free. It also offers more free storage than Evernote.