Biodiesel is a methyl or ethyl ester of fatty acids produced from vegetable oils, both edible and non-edible, or animal fat of diesel quality; and, Other bio-fuels: bio methanol, biosynthetic fuels etc

As far as the Bio-fuel programmes is concerned, bio-diesel is transesterified oil preferably of non-edible type and grown in marginal lands/non-agricultural lands where food crops cannot normally be grown. This distinction is made in order to ensure that food security of the nation is not compromised on account of these policy initiatives. For certain stationary applications where transesterification is not required, the term straight vegetable oils can be used interchangeably with bio-diesel.​