It takes a certain kind of highly detail-oriented perfectionist to be a good typesetter, and typesetting a book is no easy task.
Typesetting is key in making a print book. It comes after the editing and before the printing. It has to do with fonts, spacing, white space, chapter headings and things you don’t really notice when picking up a book but that add to the enjoyment of the reading experience.
When the typesetter is done, the publisher will get a print-ready proof to look over, to send to the author for final review, and then, when all corrections are made, to submit to the printer.
Book is printed, voila! Another book is launched out into the world of happy readers.
Hooray for the skilled typesetter!
Here’s a video discussing looking at the origins of typesetting: