PostScript is a page description language, a protocol that is used to communicate between applications (like Adobe InDesign, QuarkXPress or MS Word) and output devices, like laser printers or platesetters, that are equipped with a PostScript interpreter. PostScript can also be used to exchange data between applications themselves and it forms the basis of the PDF file format.
Several pages on this site go into more detail about PostScript:
- The purpose of PostScript
- The history of PostScript
- Postscript is a programming language
- Language specific details
- PostScript is an interpreted language
- Alternatives to PostScript
If you are a programmer or want to delve a little deeper, you will also find an interesting introduction to PostScript on this site.