Vedic culture is the earliest culture of this world. It is based on the fundamentals of Vedas. Yajna (a ritual also known as Hawan or Homa, which usually involves offerings to the holy fire) is the heart of Vedic Dharma (Vedic code of conduct). The tradition of Yajna has been in existence since time immemorial in Aryavartta (the land of Aryans, an ancient name of India), the country now called India. Many types of Yajna have always been in practice.
The word Yajna is derived from the Sanskrit word Yaj, which implies three meanings, i.e. Devapuja(worshipping deities), Sangatikaran(to accompany the appropriate) and Daan(donation). Yajna fulfils our material desires. The legendary King Dashrath (from the epic Ramayana) also had to conduct the Putreshti Yajna (A Yajna to get a son). It was Shringi Rishi who conducted this Yajna.