The Sikh marriage is four circuits of the Guru Granth Sahib Ji while the four Lavan of Guru Ram Das Ji are sung, one before each round. There is no priest, no fire, no exchange of vows and no giving away.
The Lavan describe four stages of a relationship with the divine, and the marriage is placed inside that frame rather than treated as a contract.
The rite was contested through the nineteenth century, when many Sikh marriages were performed by Brahmin priests with Vedic rites. The Anand Marriage Act of 1909 gave the Sikh form legal recognition, which was a Singh Sabha campaign and one of its clearest victories.
The Act was amended in 2012 to allow registration of Sikh marriages as such. Several countries have separate provision, and Pakistan's Punjab passed its own Sikh marriage law in 2018.
Around the ceremony sits a much larger set of customs which are not Sikh in origin and are not prescribed: the milni, the jago, the chooda, the sagan, and a scale of expenditure that has become a social problem in its own right.
The ceremony is the four Lavan of Guru Ram Das Ji, sung one at a time, with the couple circling the Guru Granth Sahib Ji after each.
The ceremony takes about forty-five minutes, can be performed by any Sikh who can read the Guru Granth Sahib Ji, in a gurdwara or in a house, and costs nothing. Everything expensive about a Punjabi wedding happens outside it.
The four stanzas describe a progression rather than a contract, and the ceremony has no vows, no priest and no giving away. What surrounds it in practice is another matter entirely.