This paper presents a structural framework for understanding how coherent systems arise, persist, and change. It identifies a minimal relational architecture—generativity, boundary, and expression—that governs the formation, stability, and transformation of systems across domains. A system arises when these three functions align to produce a stable pattern; it persists by continually regenerating that alignment; and it changes when the balance among them shifts, leading to adaptation, reorientation, or collapse. The framework is scale‑free and substrate‑independent, applying to physical, biological, cognitive, and social systems without reducing one domain to another. By articulating the invariant structure behind coherence, the paper offers a unified account of how reality produces stable, evolving forms.