Baishnab (Vaishnava) denotes followers of Vaishnavism—worship of Vishnu as Supreme. It is a religious tradition, not a caste. Adherents come from many castes (Brahmins, Kayasthas, Vaidyas, Sadgopas, etc.), and not all members of those castes are Vaishnavas.
Vaishnavism profoundly shapes Bengal’s cultural and spiritual landscape.