Unity Core

MonoBehaviour Lifecycle

Awake          → once, per script instance, even if disabled
OnEnable       → each time GameObject/component becomes active
Start          → once, just before first Update, only if active
FixedUpdate    → fixed timestep (default 0.02s); physics writes here
Update         → every frame
LateUpdate     → after all Update; camera follow, IK adjustments
OnDisable      → when component/GO becomes inactive
OnDestroy      → when component/GO is destroyed (or app quits)

Order across objects: Awake/OnEnable for ALL objects, then Start for ALL, then per-frame loops. Tweak per-script via Edit > Project Settings > Script Execution Order — sparingly.

ScriptableObject — data assets