DVI (Device Independent File Format)
From Just Solve the File Format Problem
DVI (Device Independent File Format) is a document format primarily known for being the output format of the TeX typesetting software.
The file specifies which fonts to use (although not the fonts themself), and where to put the characters on the page; it also supports "rules" (filled rectangles) and "specials" (which can be used for specifying anything that DVI doesn't already do). There are ten 32-bit numbers assocated with each page; normally, the first of these numbers is the page number, and the rest are unused.
DVI supports 32-bit characters, although TeX only uses 8-bit characters. DVI also supports changing the units of measurement, although in the case of TeX, they are fixed to 4736286.72 units per inch.