The primary function of the chloroplast is to facilitate photosynthesis, the process by which plants, algae, and some bacteria convert light energy into chemical energy. Chloroplasts contain chlorophyll, the pigment that absorbs sunlight, initiating the transformation of carbon dioxide and water into glucose and oxygen. This process is essential for providing energy to the plant and producing oxygen as a by-product. Chloroplasts also play vital roles in metabolism and synthesizing other important compounds, making them critical for plant health and ecosystem sustainability.