LaTeX is a system for preparing documents to be printed or displayed. It is built on top of the Donald Knuth's TeX typesetting system.
From version 0.48, Inkscape has a special PDF+LaTeX output option (and for EPS/PS too), described in this PDF: SVG in LaTeX.
See the TeX Users Group website for the latest news on TeX and LaTeX. If you want to create documents easily using the LaTeX system, consider LyX, which provides an easy GUI frontend to the inner workings of TeX.