Reference

This asset points at another one: the event's venue, the article's author, the product's category. What is stored is the target's identity, not a copy of its fields — rename the venue and every event pointing at it is current, because nothing was duplicated into the pointing asset. One kind, two shapes:

A reference targets a page (by path) or a record asset (by id), and at render it wakes to the resolved target — the template never follows anything by hand.

When not to use it

• A value that should freeze — a price as sold, a name as it was. A reference stays live; copy the value into the asset when history must not move.
• An external link — a URL field. References point inside the site.
• A closed vocabulary — three legal statuses are options, not references to three records.