Vedic Yajnas Srauta yajnas or sacred ones.
Paka Yajnas — ordinary rituals done easily as a basic duty
Havir Yajnas — occasional rituals done with some effort for attaining various things
Soma Yajnas — rare rituals with high levels of complexity done for world happiness
Each of these 3 classes have 7 types of Yajnas.
Paka Yajnas — offering of food made through the year at home. Agrahayani and Sravani are the key models on which others are based on.
Pitru Sraddam — done to honour ancestors every year
Parvana Sradda — performed for
the ancestors every month
Ashtaka — performed on the 8th day after full moon during the winter months for fathers
Sravani — every night from the fullmoon of Sravana month to the Margasirisa month there is a sarpabali (offering to the snakes) done to ward off harm from snakes
snakes during the rains.
Agrahayani — offering of kheer/payasam during the full moon of Margasirisa month
Chaitri — it is an offering made to Shiva where 4 roads meet during the fullmoon of Chaitra
Ashvayujih — simple food offering made to Shiva during the month of Ashvini
Havir Yajnas — offering done through fire, the first 4 at home and last 3 at Yagashala. The Ishhti is the key model for this
Agnihotram done twice every day keeping the ritual fire burning constant
Darsapurnamasam rituals (ishhti) done every fortnight, usually on the Prathama
Piṇḍapitṛyajña — done in the afternoon of newmoon
Agrayana — done after every new crop, delivering the first fruit
Chaturmasya — done every season (4 months)
Nirudha Pashubandha — done twice a year during summer and winter solstice
Sautrāmaṇī — it is a sacrifice made
with the soma ras (which is not alcohol) for Indra with a small amount partaken by the priests.
Soma Yajnas — these are long, hard sacrifices always done outside home usually accompanied by musical stotras from the Samaveda. While Haviryajnas use ghee as its main ingredient.
Hotr (Rig), Advaryu (Yajus), Udgata (Samaveda) and Brahma. Each of these are assisted by 3 priests — a total of 16 priests.
Agnistoma — a 5 day long yajna made during spring with 12 sastras (Rig) and 12 stotras (Sama) usually for the ancestors
Atyagnishtoma — similar to above
but with 15 sastras and stotras and with an added sacrifice for Agni
Shodasi — similar to the above with 16 sastras and stotras and a ram is offered to Indra
Vajapeyah — a 17 day long sacrifice made for bountiful crop where the sacrificer is bathed in food. When done by
kings it is donw with chariot race, arrow shots and yajamana climbing up a pole
Atirata — done with 29 stotras and sastras
Aptoryama — the longest one with 33 stotras and sastras
Aswamedha Yajna — an emperor to proclaim his absolute superiority
Rajasuya Yajna — a consecration of the king
Punabhisheka and Aindra Mahabhisheka — offerings done during coronation
Purushamedha Yajna — a symbolic one that is never done
Sarvamedha Yajna — a 10 day
sacrifice at the end of which the king gives away all his wealth
Vajapeyah Yajna — refer to the Soma Yajna above
Credit on goes - Balaji viswanatham ji 🙏 sir