'Pitri' stands for dead forefathers. This yagnya pertains to the duties of human beings to their dead forefathers or ancestors. Shraddha and Tarpana or offering of rice and water to departed forefathers at the time of death and also regularly each year on their death anniversary is called pitri yagnya. This offering reaches the dead ones and brings much satisfaction to them. They then bless their offsprings. Offerings to the forefathers generally stands for three generations, dead parents, grand parents and great grand parents. Offerings not specifically meant for these three generations can reach anybody even those who are not in the family lineage. All departed human beings do benefit from these offerings, those in the family lineage benefit directly because the offerings are done in their name. When the offerings are not done with specific name then the benefit goes to all.
This yagnya pertains to human duties towards the sub-human species; plants and animals. Care, protection and nourishment to sub-human species is called Bhuta yagnya. We human beings derive our food from the lower species so our duty is to take care and nourish them. Before taking food, it is mentally first offered to God, Deities then a portion given to near by animal, a cow or dog or birds and then eaten. This is called Bhuta yagnya.
This yagnya pertains to our duty to fellow human beings. A guest in the house is considered as God in human form in Indian tradition. So feeding a guest is an honored duty. Any kind of service offered to the suffering humanity is Nri yagnya.
This is the third stage of human life from 50 to 75 years of age. The word
'vanaprastha' means to go to the forest and dwelling there. In modern times this will mean, staying in a spiritual environment like an ashram or monastery or staying in the house but seeking solitude, silence, avoiding unnecessary socialization or company. During this period the mind is trained to detach itself gradually from all family, social, professional or any other obligations and free oneself from all worldly responsibilities. A systematic and thorough study of the sacred scriptures is undertaken under an able teacher or different teachers as per the needs. All desires of the mind at this stage must either be fully satisfied or given up, so that the mind can fully move on to the next stage of life. This stage is a preparation for the last and most important stage of life.
This is the last stage of human life and begins after 75 years of age and ended with death. At this stage life should be dedicated wholly for spiritual growth. The man with his wife should give up family environment and seek out a secluded dwelling away from the worldly atmosphere generally in a protective ashram. They may stay in their own houses but never interfere with children and their activities. The rest of the life should be devoted to spiritual practices till death. Those who choose to stay in an ashram, should give up their family name and enter the
renunciants's order of life. This is called sannyasa and the person a sannyasi. The sannyasi's at this age perform an important duty. They act as teachers for the younger generation. As