getOwnPropertyDescriptor returns complete property metadata: 1) value: current property value, 2) writable: whether value can be changed, 3) enumerable: whether property appears in loops, 4) configurable: whether property can be deleted/modified, 5) Returns undefined for non-existent properties, 6) Essential for property attribute inspection, 7) Used in property manipulation/inheritance implementations, 8) Important for understanding property behavior.