# About layer 0

> The parts of Occurrent that work with CloudEvents.

[Layer 0: CloudEvents](/docs/layer-0/)

Everything in this chapter works with `CloudEvent`. Nothing here knows about your domain events. Most applications use these parts through [layer 1](/docs/layer-1/), which converts between CloudEvents and domain events for you, but it’s worth knowing what happens underneath, since this is how your events are stored and delivered.