Introduction
Originally, LaTeX produced output in the Device independent file (DVI) format. This is still supported, however, today there exist newer page description languages, such as PostScript (PS) and the most popular Portable Document Format (PDF).
There are converters from DVI to PS, from PS to PDF, and also directly from DVI to PDF. A modern TeX compiler called pdfTeX can directly generate PDF output. This, combined with the LaTeX format is called pdfLaTeX, and it is pretty much the standard today.