Why my injet is better than a multi-zillion dollar book printer

Unfortunately our Visual Markets report is still not ready for purchase. Myself and our copy editor have learnt the hard way about images for book printing (I think he already knew .. it was mostly my problem). How is it that I can print out a report with images that look perfectly fine on my inkjet, but when it gets printed on the multi-zillion dollar book printer, they look crap! Now my graphic designer daughter just laughs and tells me I have no idea. And she's right. I absolutely have no idea why this is so .. but I have now changed all the 40+ images to higher resolutions to suite the multi-zillion dollar book printer.....maybe the printer manufacturers and the book printing folks have conned us all :)