Bioenergy is a renewable energy source derived from biological materials such as plants, algae, agricultural residues, and organic wastes. It plays an important role in reducing dependence on fossil fuels and addressing global energy and environmental challenges. Biotechnology supports sustainable energy production by improving biofuel generation and biomass conversion processes. Major bioenergy forms include bioethanol, biodiesel, biogas, and algal biofuels. Bioethanol is widely used as a substitute for gasoline, while biogas is produced through anaerobic digestion of organic waste. Algal biofuels are emerging as a promising option due to their high productivity and carbon dioxide absorption capacity. Biofuels are classified into first, second, and third generations based on their raw materials and production techniques. Although bioenergy offers environmental benefits, improper large-scale production may lead to issues such as soil erosion, water pollution, and greenhouse gas emissions. With increasing energy demand and depletion of fossil fuels, bioenergy provides a sustainable alternative for future energy needs.