The Sanskrit word Kriya refers to action or activity. In its cosmic usage, Kriya is one of the three primal and all-pervading Shaktis, the other two being Iccha (will) and Jnana (knowledge).
Within the International Nath Order, Kriya is Action—doing as a power. It is one side of the triad of occult accomplishment: Will, Knowledge, and Action. That triad is not the same as Insight, Intuition, and Imagination, the three super faculties. Kriya here is not a branded yoga system and it is not a grade of the Order. It is the current of action itself. It is worked in sadhana toward Siddhi. The three Shaktis are listed together on Keywords.