The Vedic system recognizes the validity of several forms of marriage:
Brahmana, in which the father of the bride sends an invitation to a properly qualified man and entrusts the girl to him; the purpose of the marriage is the joint performance of the traditional religious duties
Daiva, in which the girl is married to a properly qualified brahmana who was invited to perform a sacred ritual; the purpose of the marriage is to perpetuate the good results of the sacrifice and to protect society in general
Arsha (of the Rishis), in which the married couple offer a symbolic gift of a bull and a cow (sacred animals considered the father and mother of human society) to the girl’s parents; the purpose of the marriage is cooperation in the study and practice of spiritual life
Prajapatya, in which the girl chooses a suitable husband directly or indirectly (for example in svayamvara tournaments); the purpose of the marriage is the birth of a qualified progeny that will continue the dynasty
Gandharva, in which the girl and boy declare their love for each other (this is also the specific ritual for gays and lesbians, according to the 12th century commentator Jayamangala) and exchange vows and garlands; the purpose of the marriage is romantic desire and sensual pleasure – as exemplified in the story of Shakuntala and Dushyanta
Rakshasa, in which the girl is abducted from her home against the will of her family; this type of marriage is also popular with Kshatriyas who want to overcome the blind opposition of the girl’s family to her wishes (as in the cases of Krishna’s wife Rukmini and sister Subhadra, who married Arjuna)
Asura, in which a girl and her family receive gifts, boons or wealth from the prospective husband to convince them of his good intentions; the most famous example in puranic history is Shantanu, who married Satyavati by pledging exclusive succession rights to Satyavati’s sons
Pisacha, in which a girl is seduced into a sexual relationship by flattery, emotional pressure, mental manipulation, intoxication (with wine etc.), or approached while she is sleeping and more vulnerable. The purpose of the pisacha marriage is mere satisfaction of sensual pleasure but still the women involved and the children conceived in such relationship are considered perfectly respectable by society.