Christmas trees are decorated to bring joy and beauty into our homes during the holiday season. Decorating a tree is a tradition that goes back thousands of years and is a symbol of the season. It's a way to create a warm and inviting environment for our loved ones and to celebrate the birth of Jesus. Trees are also decorated with lights and ornaments to symbolize the light of Christ and the beauty of creation. So, it's a way to bring a little bit of the outdoors in and create a festive and cheerful atmosphere for the whole family.