You delete a folder on your laptop. A moment later it disappears from the cloud and your other computer. Nothing malfunctioned: synchronisation did exactly what you asked.
Two different jobs
Synchronisation keeps a working collection aligned across devices. A backup keeps a recoverable copy or history. A service may offer both, but the presence of a cloud icon proves neither how far back you can go nor what you can restore.
Apple documents that deleting an iCloud photo removes it from other devices using the same account. Microsoft provides recovery through the OneDrive recycle bin. Those features have conditions; they are not a promise of permanent history.
Ask a more useful question
Instead of “Are these files in the cloud?”, ask “Could I recover this folder as it was before yesterday’s mistake?” Find the answer in your service’s version history and recovery documentation.
Also consider access. A copy that requires the same unavailable account may not help during an account lockout. Write down which recovery route depends on which account, device or password.
Make a small, harmless test
Create a disposable document. Let it sync, change a sentence and find the earlier version. Then delete only that test document and try the documented recovery process. Do not experiment on the only copy of anything valuable.
The exercise reveals more than a reassuring green tick. You learn where recovery happens, what is preserved and which steps are awkward.
Give important files another way back
Keep a separate copy of irreplaceable work outside the folder that mirrors your everyday changes. Decide how often to refresh it and test opening a few files. An old backup may miss recent work; an untested one leaves you guessing.