A Microsoft file hosting and synchronization service.
When you sign in to OneDrive on the web, do you see the files under a different folder or under a different Microsoft account? OneDrive keeps deleted files in the Recycle Bin for up to 30 days for personal accounts, and large changes often appear in account activity. If files are not in the Recycle Bin, I'm sorry it cannot be recovered.
You can still check just follow these:
• Sign in at onedrive.live.com with each Microsoft account you use, check if files exist under another account
• Open OneDrive Recycle Bin and sort by Date deleted, also check if large folder deletions appear
• Open OneDrive Settings, select Restore your OneDrive, review restore points from the last 30 days
• Check account activity at account.microsoft.com to see file deletions or unknown sign ins
• Check storage status in OneDrive Settings, a full account sometimes blocks syncing and file changes