### What is a driver?

A driver is a program that takes as input a DVI file (DVI files) and (usually) produces a file that can be sent to a typographic output device, called a printer for short.

A driver will usually be specific to a particular printer, although any PostScript printer ought to be able to print the output from a PostScript driver.

As well as the DVI file, the driver needs font information. Font information may be held as bitmaps or as outlines, or simply as a set of pointers into the fonts that the printer itself 'has'. Each driver will expect the font information in a particular form. For more information on the forms of fonts, see `pk` files, `tfm` files, virtual fonts and Using PostScript fonts with TeX.