Explanation:

First Generation Biofuel-The  biofuels which are directly produced from food crops i.e. starch, sugar, animal fats, and vegetable oil
Second Generation Biofuel-They are also known as advanced biofuels which are manufactured from various types of biomass and non-food crops.(Biomass is a wide-ranging term meaning any source of organic carbon that is renewed rapidly as part of the carbon cycle)
Third Generation Biofuel-They are mostly made up of specially engineered energy crops such as algae as its energy source.  The algae are cultured to act as a low-cost, high-energy and entirely renewable feedstock.
Fourth Generation Biofuel-They are aimed at producing sustainable energy but also on way of capturing and storing CO2.This process differs from second and third generation production as at all stages of production the carbon dioxide is captured using processes such as oxy-fuel combustion.
2nd Generation biofuels have been developed to overcome the limitations of first generation biofuels.
As 2nd generation are produced from non-food crops such as wood, organic waste, food crop waste and specific biomass crops, therefore eliminating the main problem with first generation biofuels i.e. consumption of food resources.
They aimed at being more cost competitive in relation to existing fossil fuels.
But they still consume land resources so we are moving beyond them.
India’s first ‘Second Generation Bio-fuel Refinery’ is to be set up in Bathinda, Punjab.