How Lasco works
The Lasco app syncs your library to several remote storages at once. That redundancy is what keeps your data safe.
Subscribing to Lasco Cloud gives you two of them: on the 400 GB plan, two remote storages of 400 GB each.
You are free, and in fact encouraged, to add a third one of your own: an S3 server, a NAS, a USB drive.