Carotenoids are a large family of over 1,100 naturally occurring pigments synthesized by plants, algae, and bacteria, characterized by their conjugated polyene chains that provide vibrant yellow, orange, and red colors in fruits, vegetables, and other organisms. As tetraterpenoids, they consist of 40 carbon atoms and are divided into carotenes (hydrocarbons like β-carotene) and xanthophylls (oxygenated derivatives like lutein). They play crucial roles as antioxidants, scavenging free radicals and protecting cells from oxidative stress, and as precursors to vitamin A in animals. In photosynthesis, carotenoids assist in light harvesting and photoprotection by dissipating excess energy. Health benefits include potential reduction in chronic diseases such as cancer and cardiovascular issues due to their anti-inflammatory properties. Physically, they are lipophilic, stable in non-polar environments, and sensitive to light and heat, which can lead to isomerization or degradation. Environmentally, they contribute to biodiversity as essential dietary components for animals. This description focuses on β-carotene as a primary example, with a molecular structure featuring two β-ionone rings connected by a polyene chain, making it a vital nutrient in human diets from sources like carrots and sweet potatoes.