And more. Long story, but go over to Adobe and take a look.
The idea is that you have your referenced originals, which are backed up however you back up and/or archive such files.
The Lr data, which includes adjustments, presets, publishing info, etc etc is in a database, which is backed up at intervals you decide on, in that a copy is made. But that itself must be backed up, and unlike the photos themselves it changes more often.
People store both photos and Lr catalogs on Dropbox, and while iCloud is no Dropbox, I imagine you could copy both there. Whether that's efficient or cost effective, I can't say since I don't use it.