Marriage is considered as the most platonic, pure and eternal bond of relationship between a man and women in Indian culture and tradition. In Tamil Nadu as in most part of the Indian society, the first step in marriage is the analysis of the horoscope or jathaka matches between the bride and groom, which will dictate whether or not a marriage is considered.

Horoscope matching also called Jathaka Porutham is a system devised by the ancient sages seering to analyze the marital compatibility of two people by examining their birth stars and moon signs, ascertaining Koota Agreement, a method of matching horoscopes where twenty kootas are usually recommended, although only ten or sometimes eight are considered for match-making.

There are 28 Nakshathras, stars in an oval round called the Zodiac and the Navagrahas, the nine planets, which transit the Zodiac, a heavenly constitution exerting their combined astral influences on human beings. Each koota or porutham has a specific role or a part to play, and among them the most important ones leading to a smooth sailing marriage are dina, gana, rasi, yoni and rajju.

• The presence of Dina koota agreement ensures that the husband and wife remain healthy and free from all sorts of diseases and will enjoy all comforts and a long lease of life.
• The presence of Gana koota agreement ensures compatible sex life, and the matching of the human minds and their temperaments.
• The presence of Mahendra koota agreement assures assures progeny or children in a larger measure.
• The presence of Stree Deerga koota agreement ensures accumulation of wealth and all round prosperity.
• The presence of Yoni koota agreement ensures sexual compatibility, while confering mutual love between husband and wife.
• The presence of Rasi koota agreement ensures the continuation of one's family through the birth of a son. If there is no progeny or issue, his family and tradition will end with him. Another school of thought interprets it as cordial relationship between the daughter-in-law and her in-laws.
• The presence of Rasiyathipaty koota agreement ensures santhanam, progeny denoted in Rasi Koota, and refers to the friendship between the lords of the birth stars of the girl and boy.
• The presence of Vasya koota agreement assures mutual love and attachement, and confers mutual affection between couples.
• The presence of Rajju koota agreement ensures a long life for the husband, and bestows on the girl living happily with the husband for the long time.
• The presence of Vedha koota agreement ensures happy and prosperous married life, and wards of all evils and pitfalls in married life.

Nakshatra porutham or Star Matching is important, although it cannot indicate on its own any dosham in the jathagam matching, such as sevvai dosham, dosha samyam, dasa sandhi, also major factors that may affect the marriage positively or negatively. Therefore, in addition to the nakshatra matching, people make use of the Prasna Jothidam to identify any ill effects in the porutham matching, when the rasi or nakshatra porutham is found to be matching.