What kind of yoga is bhakti?
Bhakti-yoga is the relationship of loving service exchanged between a bhakta—devotee of Krishna, and Bhagavan—the Supreme Person. It is the constitutional, natural condition of our existence, but our natural inclination to serve God with love is now covered over by misconceptions about who we are (the self) and what the goal of life is. Bhakti-yoga is actually the goal of life.
In this often-quoted passage from Srimad-Bhagavatam, 7.5.23-24, the devotee-king Prahlada lists the nine main recommended practices of bhakti, any one of which can revive our natural consciousness:
"Hearing and chanting about the transcendental holy name, form, qualities, paraphernalia and pastimes of Lord Vishnu [Krishna], remembering them, serving the lotus feet of the Lord, offering the Lord respectful worship with sixteen types of paraphernalia, offering prayers to the Lord, becoming His servant, considering the Lord one's best friend, and surrendering everything unto Him (in other words, serving Him with the body, mind and words)—these nine processes are accepted as pure devotional service. One who has dedicated his life to the service of Krishna through these nine methods should be understood to be the most learned person, for he has acquired complete knowledge."
As bhakti-yoga gains popularity, so also do misunderstandings of its meaning.
Some believe that bhakti is an emotional state which can be attained through physical yoga or by chanting any kind of mantra. But this isn't supported anywhere in Vedic teachings. Anyone's natural bhakti can be uncovered through the scientific process of practicing bhakti-yoga.