When working in Excel on a file system, you can share the file so that multiple people can edit it, even simultaneously. However, you may wonder how to do a similar thing in Microsoft SharePoint. One way to do this is to publish portions of an Excel file as Web Parts. When editing a Web Part page, you can add an Excel Web Access Web Part from the Business Data category. This allows you to attach a named portion of an Excel workbook into the Web Part. Based on the properties you select and permissions of the users, you can allow Office Online users to edit the Excel document that they see on the web page.