Biryanis differs from region to region and ingredients used also differ a bit.  So there are varieties in Biryani. However, Biryani is classified as Kacchi or raw Biryani and Pakki or cooked Biryani! In the Kacchi  Biryani raw marinated meat is layered with raw rice before being cooked together. The pot is usually sealed (typically with wheat dough) to allow cooking in its own steam and not opened till ready to serve. In Pakki Biryani the partially cooked meat and partially cooked rice are layered and cooked. Then we have Navratan biryani which is sweeter, richer and uses cashews nuts,raisins and fruits like apples and pineapples.   Biryani based on the ingredients like Beef biryani or Kalyani Biryani. Or the region in which they were developed, for example, Sindhi biryani developed in the Sindh region of what is now Pakistan, and Hyderabadi biryani developed in the city of Hyderabad in South India. One such dish is Tehri which was developed for the Hindu Bookkeepers in the Muslim Courts.