When used with SharePoint Server 2016, Office Online Server provides Word Online, Excel Online, PowerPoint Online, and OneNote Online. How SharePoint Server uses Office Online Server for viewing and editing Office documents This functionality is provided by a feature known as Online Viewers.

With Office Online Server, users can also view Office files that are stored outside SharePoint Server, such as those in shared folders or other web sites. Office Online Server requires dedicated servers that run no other server applications, however, you can install Office Online Server on virtual machines if needed. An Office Online Server farm can provide Office services to multiple on-premises hosts, and you can scale out the farm from one server to multiple servers as your organization's needs grow. These products, known as hosts, include SharePoint Server, and Exchange Server. Office Online Server works with products and services that support WOPI, the Web app Open Platform Interface protocol. Office Online Server is an Office server product that provides browser-based file viewing and editing services for Office files. Are you looking for help with Office Online on your desktop or mobile device? You can find this information by searching for 'Office Online' on Office Support.

Microsoft office online