Office web and mobile apps

The web app and mobile app versions of Office give you the ability to create, access, edit, and share Word, Excel, PowerPoint, and OneNote files through OneDrive for Business, SharePoint, and Microsoft Teams. You also get the ability to co-author documents with those who have edit access. Co-authoring is the ability to open and work on a document simultaneously with others. Office web and mobile apps are included in the Pro Plus plan, as well as all Business and Enterprise plans except E1. For E1, only the web apps are available.