The primary source of non-renewable energy that cannot make up for its losses over the course of years is fossil fuels, which are also referred to as conventional fuels. According to the findings of the 2019 World Energy Global Statistics Review, both global emissions of carbon dioxide and primary energy consumption went up by 0.5 percent and 1.3 percent respectively, over the previous year. These elevated charges are being implemented as a precautionary measure for both people and the environment. On the other hand, renewable resources, such as biofuels, create fewer greenhouse gas emissions, cause less pollution, and have the potential to be manufactured from biomass in the form of organic waste. When seen from a global perspective, biofuels have demonstrated that they are viable alternatives for lowering emissions of greenhouse gases and finding solutions to challenges inherent in the need for energy. There are several efficient sources for the production of biomass, and these sources may be separated into three distinct types, namely, first, second, and third generation biofuels. The first generation comprises biomass derived from edible crops, the second generation contains biomass derived from lignocellulosic materials, and the third generation contains biomass derived from algae and holds the potential for renewable resources. This paper provides a summary of several forms of biofuels, including biodiesel, as well as their comparative studies, production methods, and applications from the point of view of the environment.
