Kriya: "act, doing"

Bhakti: "devotion, worship, faithfulness"

These words relate to aspects of Yoga.

Kriya refers to spiritual practices. In the case of Yogananda, he was a student of the basic level of his tradition, a level called Kriya. In that level he learned meditation and pranayama. So, that was his Kriya.

Bhakti refers to remembrance of the Divine, especially through prayer, rituals, and song, all of which enflame the heart.

Naturally, all of this is fundamental in Gnosis.