If you are a mobile device user, you know that it’s not always possible or convenient to connect to SharePoint every time you want to read or modify a document. In SharePoint 2016, you can work with your documents offline. You can synchronize, or sync, a SharePoint library to your device. This process creates a copy of the library on your device in the SharePoint folder, under the name that combines the name of the source SharePoint site with the name of the source library, with a hyphen in between—for example, Team Site-Documents. You can modify the location to one of your choosing. You can then work with files in the library by using File Explorer. When working offline, you can view and modify the content in the same way you can when working in SharePoint. Updates to the files synchronize back to SharePoint when you are back online. For example, if you create a new document in a library folder on your device, it will be synced back into the source library when you are online.
To sync a library to your device
In SharePoint, go to a library that you want to sync to your device.
In the body of the page, above the list of documents, select Sync.
Confirm that you want to sync the library by selecting Sync now in the confirmation dialog.
If the browser security dialog box appears, select Allow.
In the message box that appears, select Sync Now to confirm the root location and start the sync.
A message appears confirming that the sync has started. The full path to the location is shown, including the root, the SharePoint folder, and the subfolder that is named after the site and the library, with a hyphen in between; for example, C:\Sharepoint\Team Site-Documents.
If you want to see the files as they come in, select Show my files.