OneDrive Files On-Demand are now available to Windows Insiders in Windows 10. OneDrive Files On-Demand still works the same way as OneDrive Placeholders for the most part. Once you add your OneDrive account to your Windows 10 PC, OneDrive will show all of your files in the File Explorer — but it actually won’t download the file on your device, enabling you to save a lot of space. Instead, it will only download a file or folder once you actually open it.
If you don’t want all of your files to be online and you might want to save some files locally so that you can access them when you’re offline. To address this issue, Microsoft has added a new “Always keep on this device” option which will let you download a specific file or folder locally so that you can access them when you don’t have an internet connection.