Crown Jewels
Think of your crown jewels as the 'must-save' items in a house fire; they are the few things that, if lost, would mean you have nothing left to rebuild with. You identify these most important items first so you can put them in the safest possible vault.
Crown jewels are the critical subset of your organization's data, models, and infrastructure that represent existential risk if compromised. In a security program, you prioritize these assets for protection because they are the primary drivers of your business value and the foundation of your security roadmap.
The small set of assets (data, models, systems, relationships) whose compromise is existential; the focus of a defensible AI security posture ('AI's value comes from your data; its security comes from your framework'). The starting point of the GOVERN then IDENTIFY then SECURE then VALIDATE roadmap. (C4AIL / Practical Cyber.)