Biofuels such as biodiesel, bioethanol, biomethanol, and biomethane are fuels produced from biomass, which includes organic matter. While biofuels reduce net GHG emissions by absorbing CO2 during their growth, their overall impact depends on the balance between CO2 absorbed and emitted during production and combustion. First-generation biofuels from edible crops have a problem of competition with food and may lead to higher food prices. Additionally, the effects of land use change (LUC), such as deforestation, can exacerbate GHG emissions. As a result, the EU and IMO have developed guidelines for biofuel criteria, focusing on WtW GHG emissions intensity from production to use of biofuels. In the future, advanced biofuels produced from non-edible biomass, may offer a more sustainable alternative. E-fuels produced from renewable hydrogen and captured CO2 are also gaining attention, as they can reduce WtW GHG emissions and be used without modifying conventional fossil fuel-based systems. However, the benefits of e-fuels depend on the source of CO2, because using of non-renewable CO2 from fossil fuels may not reduce the WtW GHG emissions sufficiently. While challenges remain, both biofuels and e-fuels are seen as key options for achieving net-zero emissions in the future.