शक्तिः सिद्धिश्च ॥ कZ_०६.२.३० ॥
śaktiḥ siddhiś ca
শক্তি এবং সিদ্ধি (সাফল্য-ক্ষমতা)।
Śakti is the underlying capacity/resources to act; siddhi is the practical ability to convert that capacity into achieved outcomes.