If you'd like to keep a copy of your files on your computer and have them automatically update on OneDrive the next time you're online, synchronizing your files will be an important part of using cloud storage. Below, you will find links to Microsoft's information on synchronization, as well as installation instructions.
Sync Details for Windows
Sync Details for Mac
If at any point the sync isn't working as expected on your system, Microsoft also has some tips to help you figure out what may be wrong. You can also contact the IT Support Center for assistance.
Fix OneDrive sync problems