According to Osho, meditation is the formless, silent inner stillness; bhajan is that same stillness flowering into voice—feeling expressed as song, resonance, and celebration. Prayer is the heart’s address to the Whole, the devotional mood of love and gratitude that can be silent (meditative) or voiced (bhajan). They are one continuum: seed (meditation), flower (bhajan), and fragrance of communion (prayer).
Meditation is quiet inside, bhajan is that quiet turning into song, and prayer is lovingly talking to the Whole—either silently or aloud.