The types axis of Sustainable Aviation Fuels segmentation classifies SAF into five technologically distinct pathways: Hydroprocessed Esters and Fatty Acids (HEFA), Fischer‑Tropsch (FT), Alcohol‑to‑Jet (ATJ), Sugar‑based (SB), and Catalytic Hydrothermolysis (CH). HEFA, derived from vegetable oils or animal fats, presently supplies the majority of commercial SAF due to its compatibility with existing refinery infrastructure and a proven track record of meeting ASTM D7566 specifications. FT fuels, produced from gasified biomass or municipal waste, offer a high‑energy density and low‑aroma profile, positioning them for niche long‑haul applications despite higher capital costs. ATJ processes convert ethanol or other alcohols into jet‑grade hydrocarbons, enabling integration with established ethanol supply chains. Sugar‑based routes, utilizing lignocellulosic feedstocks, target future scalability by leveraging agricultural residues. CH, an emerging technology, transforms wet biomass directly into jet‑fuel range hydrocarbons, promising reduced processing steps. Each type contributes variably to the total SAF pool, with HEFA representing the largest share, while FT, ATJ, SB, and CH collectively expand the market’s feedstock diversity and resilience, a core element of Sustainable Aviation Fuels segmentation.