In the West, the wedding day is a single event. In India, the wedding is a season. The actual "wedding" is usually just a three-hour window on a specific muhurat (auspicious time), surrounded by days of festivities.
The festivities begin long before the actual wedding day. These rituals are designed to break the ice between families, bless the couple, and build anticipation.
Literally "the knot of union." A sacred cloth is tied around the bride’s chunari (veil) and the groom’s shawl. This binds them together for the Phere that follow. You cannot walk the four circles around the fire without being literally tied to one another.