Autumn foliage refers to the colorful leaves that appear on trees during the fall season. As temperatures drop and daylight decreases, chlorophyll—the green pigment in leaves—breaks down, revealing other pigments like carotenoids and anthocyanins. This process creates vibrant shades of red, orange, yellow, and purple. The phenomenon is most noticeable in deciduous trees, such as maples, oaks, and birches. Different species exhibit varying colors and timing, influenced by factors like temperature, moisture, and sunlight. Autumn foliage attracts many people who enjoy activities like leaf-peeping and photography, celebrating the beauty of nature's seasonal change.