We usually find dīkṣā translated as “initiation” because to “initiate” something is to start it, to set it in motion – and dīkṣā is the thing that starts us in a certain direction.
In bhakti-yoga, dīkṣā is the thing that starts our devotional practices, sādhana-bhakti. Dīkṣā is the beginning of yoga. By dīkṣa we are accepted into a “school” of yoga and begin to be given whatever techniques and materials the school employs in its educational process.
Dīkṣā must be followed by śikṣā, specific