A criteria-based directory assembled OVER existing business sites (a town, a niche-in-a-state, a personal collection).
A Cloud is a Doozer.Cloud directory built over existing business sites by criteria (a town, a niche in a state, a personal saved set). Clouds are unlimited (no new-site cost) because they curate sites that already exist. Stored in the clouds table; engine in includes/cloud-engine.php; rendered via the shared business card.
A personal Cloud is "My Doozer Cloud" at my.doozer.cloud. Clouds are a core surface of the flywheel.