What do local and cloud mean?
Local data is the lists, items, and other records stored on your current device. Cloud data belongs to your Lister account and is transferred to your devices through sync.
When both datasets exist, Lister may ask which one to keep during sign-in. They are not automatically merged.
Use cloud data
If your desired lists already appear on another synchronized device, using the cloud data is usually appropriate. This replaces the local data on the new device.
Keep local data
This choice uses your local dataset in place of the previous cloud dataset. It affects your existing account and its data. Read the confirmation dialog fully and back up important data first.
If you are unsure
Cancel the operation for now. Make a backup and email ask@lister-studios.com. Explain which device currently has the lists you want to keep.