Largely a combination of flavouring spices used along with taste-agents like black pepper & chilli to impart a pleasantly textured flavour to ordinary rice.
The origins of this blend can be traced back to the Mughal era.
Biryani/Pulav can either be a Veg. or a Non-Veg. preparation usually made during special occassions. It is a whole meal by itself, and is almost always the centre-piece of most Indian dinner parties. Is usually served with curry and raita (curd spiked with fresh green herbs)