Puja varies according to the sect, region, occasion, deity honored, and steps followed. In formal "Nigama" ceremonies, a fire may be lit in honour of the god Agni, without an idol or image present. In contrast, in Agama ceremonies, an idol or icon or image of a deity is present. In both ceremonies, a lamp (diya) or incense stick may be lit while a prayer is chanted or hymn is sung. Puja is typically performed by a Hindu worshiper alone, though sometimes in the presence of a priest who is well versed in a complex ritual and hymns. In temples and priest-assisted events puja, food, fruits and sweets may be included as sacrificial offerings to the ceremony or deity, which, after the prayers, becomes "prasad" – food shared by all gathered.