Taking the book to Print

The colophon is defined as 'Technical information such as edition dates, copyrights, typefaces and the name and address of the printer. In modern books usually on the verso of the title page, but in some books placed at the end'
Verso being the left page and recto the right.

I want to get it clear in my head the distinction between the role of the printer and publisher; I always saw the publisher's job as getting the material ready with any pertinent instructions and taking that to be printed. The printing company's job being purely technical.