Carotenoid is a class of organic pigments that are responsible for giving fruits and vegetables their bright colors. They are also found in algae, bacteria, and fungi. Carotenoids belong to the larger group of compounds called terpenes, which have a yellow or orange color. The most common carotenoids include beta-carotene, alpha-carotene, gamma-carotene, lutein, lycopene, and zeaxanthin. These pigments are essential for human health as they act as antioxidants that protect cells from damage caused by free radicals. They also play a role in maintaining good vision, skin health, and immune function.