Biofuels are considered as a green alternative to current energy resources especially coal, petroleum, and natural gas.Fossil fuels are depleting at an alarming rate, this causes concern over the scientific community to find renewable energy sources that can fulfill the high energy demand of the industrialized world.Widespread use of petroleum products in almost all sectors, demands for developing alternative energy sources with least environmental impacts.In contrast to fossil fuels which are exhaustible in nature, biofuels are produced from replenishable organic resources such as plants, animals, and microbes.Thermal, chem., or biol. transformation of these natural biomass results into the solid, liquid, and gaseous biofuels.The term "Biofuel" is generally used for liquid or gaseous fuels, used as transportation fuels.Examples of such biofuels are Bioethanol, Bio hydrocarbons, Biodiesel, Biogas, and Syngas etc.These kinds of fuel are finding wide acceptance in industries as well as in academia as an alternative future fuel.Chem. composition of Biofuels is similar to petroleum fuels.They are fully compatible with current automobile engines and can run onto the existing systems without any engine modification.Partial or full replacement of petroleum fuels by biofuels reduces greenhouse gas emissions and global warming.Modern scientific and technol. reforms have enabled the large-scale com. production of biofuels feasible.Many countries like the US, UK, Brazil, Australia have initiated and promoted research in renewable biofuels through policies and subsidies.Production and supply chain of biofuels decreases dependency on imports of crude oil.In fact, it enhances the energy economy by creating local income resources.These replenishable, biodegradable and eco-friendly energy reserves hold a long-term solution for a green environment and energy independent world.