The Christmas tree is a symbol of the pagan tradition of bringing a tree indoors to celebrate the winter solstice. It was believed that the evergreen tree was a symbol of life and rebirth, and bringing it inside represented the coming of spring and the return of light. The custom was eventually adopted by Christians, who used the tree to symbolize the birth of Jesus Christ. Over time, the Christmas tree became a beloved symbol of the holiday season, and today it is an iconic part of the Christmas tradition.