The main function of chlorophyll is to absorb light energy during the process of photosynthesis, which is how plants, algae, and some bacteria convert light energy into chemical energy. Specifically, chlorophyll primarily absorbs blue and red wavelengths of light, reflecting green light, which gives plants their characteristic color. The absorbed light energy is then used to convert carbon dioxide and water into glucose and oxygen, providing essential energy for the plant's growth and sustenance. This process is crucial not only for the plants themselves but also for supplying oxygen and food to the wider ecosystem.