Understand coauthoring and Add-ins
Applies to: 
Visual Studio 
Visual Studio for Mac
Note
This article applies to Visual Studio 2017. If you're looking for the latest Visual Studio documentation, see Visual Studio documentation. We recommend upgrading to the latest version of Visual Studio. Download it here
Coauthoring is a feature of Excel for Windows desktop that allows you to edit a workbook hosted in the cloud (that is, OneDrive, OneDrive for Business, or SharePoint Online) simultaneously with other users. With the addition of this feature, you may need to make adjustments to your Excel Solution in order to ensure that it works smoothly even while users are coauthoring. See About coauthoring in Excel.
Note: Coauthoring for Windows Desktop Excel was introduced in 2017 and is currently available for Office365 subscribers. Users who purchased a perpetual license to Office 2016 or earlier do not currently have access to the coauthoring feature. (Excel Online, Excel for Android, Excel for iOS, and Excel Mobile in the Windows Store also support coauthoring).