OneNote is a Windows 10 digital note-taking application that collects users' notes (handwritten or typed), drawings, screen clippings and audio commentaries for free-form information gathering and multi-user collaboration. Notes can be shared with other OneNote users over the Internet. OneNote is available as a part of the Microsoft Office suite. It is also available as a free stand-alone application for Windows, Mac, Windows RT, Windows Phone, iOS, Android and Symbian. A web-based version of OneNote is provided as part of OneDrive or Office Online and enables users to edit notes via a web browser.

Designed to function as an electronic version of a paper notebook, Microsoft OneNote is a personal information management (PIM) application for helping users capture ideas and information in different digital formats easily. In OneNote, users can enter typed text via keyboard, create tables, and insert pictures. However, unlike a word processor, users can write anywhere on a virtually unbounded document window by just clicking there. Also, users do not need to explicitly save their work — OneNote saves data automatically as the user works so information is never lost. It saves information in pages organized into sections within notebooks.

The OneNote interface provides an electronic version of a tabbed ring-binder, into which the user can directly make notes, gather and organize material from other applications. Users are able to share possibly unpolished materials — as compared to word processors and wikis, which usually target publishing in some way. Users can move pages within the binder and annotate them with a stylus or word-processing or drawing tools. Users may add embedded multimedia recordings and web links.

One can search images (e.g., screen captures, scanned documents, photographs) for embedded text-content. It also searches "electronic ink" annotations as text, and phonetically searches audio recordings on a text key. It can replay audio concurrently with notes taken during the recording.