Back in the 8-bit era (and for a little while afterward), games and other software came in boxes. So to produce a software product, you had to not only write the code, but also create and print all of that supporting material. A product was a physical thing like a cassette tape or cartridge or disk and the boxes often included thick manuals - sometimes even spiral bound! There were games that had manuals with dozens of pages filled with wild concept art, maybe some stickers, etc.
@bigzaphod I have my boxed version of Logic Pro 7 at home, and I love the fact that it has paper manuals for all the instruments. It just feels complete.