[LiveComponent] this.component.emit() has data argument. What does it do?

[jorismak]

As stated in the title,

if following the documentation to send live-component-events from Javascript, you use getComponent() to get a Component instance, and call emit() on that.
Then you use an attribute on the PHP side to trigger an action when that event is received.

The emit() call in Js has a 'data' argument. What does this do? Is it random data to be given to the event? If so, how can I access it from the PHP side of things?

[jorismak]

Never mind, reading the docs is hard these days apparently :(.