The major difference between newspapers and periodicals on one hand and books on the other hand is that the former are supported by advertising. That means that their content and their production are both influenced by the interests of big advertisers, though editorial staffs wage a ceaseless war for independence from the dictates of advertising sales departments, with publishers playing arbiter. Book publishing is a little different. On the other hand, job descriptions for both editorial and production functions are remarkeably consistent throughout publishing. Writers create text.
Editors make sure it's the right text for the publication.
Proofreaders make sure it has all its commas in the right place and all its proper nouns capitalized, not to mention checking about 10,000 other points of style and grammar. Finally, a production designer works with the printing plant to make sure that when paper comes off the press the colors are true, the pages are in the right order, and the book or magazine is what the publisher ordered. The process, throughout, demands strict attention to detail and unwavering adherence to specifications. Publishing is also an online industry. Most print-based newspapers and magazines have versions on the Web.