PostScript is a page description language (PDL) developed by Adobe Systems. It is primarily a language for printing documents on laser printers, but it can be adapted to produce images on other types of devices. PostScript is the standard for desktop publishing.
All major printer manufacturers make printers that contain or can be loaded with Postscript software, which also runs on all major operating system platforms. A Postscript file can be identified by its “.ps” suffix.
Users can convert Postscript files to the Adobe Portable Document Format ( PDF )
PostScript is an object-oriented language, meaning that it treats images, including fonts, as collections of geometrical objects rather than as bit maps.
The principal advantage of object-oriented (vector) graphics over bit-mapped graphics is that object-oriented images take advantage of high-resolution output devices whereas bit-mapped images do not. A PostScript drawing looks much better when printed on a 600-dpiprinter than on a 300-dpi printer. A bit-mapped image looks the same on both printers.
Ghostscript is an interpreter for PostScript and Portable Document Format (PDF) files. Ghostscript can read a PostScript or PDF file and display the results on the screen or convert them into a form you can print on a non-PostScript printer.
Text extraction from pdf file with GhostScript
gswin64c -sDEVICE=txtwrite -o output.txt input.pdf
gs -sDEVICE=txtwrite -o output.txt input.pdf