When you use Windows 8.1 or older, you wish to synchronize your folders with Sharepoint Online or Onedrive for Business. You need to download a plug-in call "Onedrive for Business". Moreover, you need to put the SharePoint or OneDrive URL manually. In Windows 10, that is easy! All you need to do, going to the folders you wish to synchronize in Sharepoint or Onedrive in your browser. Then you can see a "Sync" in the toolbar. Then you need to click; then Windows will synchronize the folder. You will see the folder in your file explorer too. No software is required to install and I tried that works in Edge and Chrome!