TeX engine (pdfTeX running in LaTeX mode) that produces PDF output directly from LaTeX source, instead of the older DVI-then-convert-to-PostScript-then-to-PDF pipeline classic TeX used. The most common default LaTeX engine in TeX Live/MiKTeX distributions and the one most LaTeX tutorials assume, though XeLaTeX and LuaLaTeX have since become preferred for documents needing modern font handling or Unicode input pdfLaTeX doesn't natively support.