The bindi is the famous red dot worn by Indian women on their foreheads that draws so much attention to Westerners. Traditionally, the bindi was made with the groom's blood during the wedding and it was he who placed it on the bride's forehead, so that the marriage bond was unbreakable. However, today, the bindi is made with makeup or, simply, an adhesive of this color is applied. What has not changed is its meaning. You have all the information in: «Indian customs«.
You have all the information in: "Indian customs".