What is Office Online?
Office Online is an online office suite offered by Microsoft, which allows users an easy way to access, view, create and edit documents using lightweight, web browser-based versions of Microsoft Office applications:
The offering also includes Outlook.com , People , Calendar and Microsoft OneDrive , all of which are accessible from a unified app switcher. The on-premise version of this service called Office Web Apps Server can be installed in private clouds in conjunction with Microsoft SharePoint and Microsoft Exchange Server .
Office Online works great with Microsoft 365 .
Office Online Screenshots
Office Online information