Biofuels generally fall into two categories, bioalcohol and biodiesel. The former, such as ethanol, is created by engineers from yeast and bacteria to break down starch from corn and other plants. Biodiesel, on the other hand, is created in refineries that use existing oil in crops such as soybeans.Vegetable oils are triglycerides extracted from plants. These oils have been part of human culture for millennia. Edible vegetable oils are used in food, both in cooking and as supplements. Many oils, edible and otherwise, are burned as fuel, such as in oil lamps and as a substitute for petroleum-based fuels.Jatropha curcas grows in tropical and subtropical regions. The plant can grow in wastelands and grows on almost any terrain, even on gravelly, sandy and saline soils.A large variety of plants that produce non-edible oils can be considered for biodiesel production. The non-edible oils, such as jatropha, microalgae, neem, karanja, rubber seed, mahua, silk cotton tree, etc., are easily available in developing countries and are very economical comparable to edible oils.