Synchronization makes sure any changes to a file on the desktop or in OneDrive for Business are reconciled so that each copy of the file reflects the latest changes.
Sync your files
Sign in to Office 365 with your work or school account.
At the top of any page in Office 365, select OneDrive. Or select , and then select OneDrive.
Note: The first time you click OneDrive, you will see some setup screens and instructions while your personal site is being set up. You may have to wait and then click OneDrive again before continuing to step 3.
On your OneDrive for Business page, click Sync.
At the prompt, click Sync Now. If the sync app is not on your computer, it is automatically downloaded.
You can click Show my files to open the synced OneDrive for Business folder in File Explorer. The folder appears in your Windows Favorites as OneDrive for Business or OneDrive - YourCompanyName.
For more information about syncing, including troubleshooting information, see Sync OneDrive for Business or site libraries to your computer.