A group of Microsoft Products and technologies used for sharing and managing content, knowledge, and applications.
Hi gigidiv,
Thanks for posting in the community.
For the “Sync” feature, you can sync your Microsoft SharePoint files (library) to a folder on your computer by the OneDrive client.(a different sync folder from OneDrive sync folder) This lets you work directly in File Explorer and access files even when you're offline. And when you go back online, any changes made to those files will sync automatically.
For your reference: Sync SharePoint and Teams files with your computer
For the “Add shortcut to OneDrive” feature in SharePoint, you can sync your Microsoft SharePoint files (library) to your OneDrive. You could access the SharePoint library in OneDrive directly. Also, if you use the OneDrive application, you could see the library folder in File Explorer.
For your reference: Add shortcuts to shared folders in OneDrive for work or school
If you have any concerns, please feel free and come back to share with us.
Regards,
George