Publishers publish the game <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />
In it's barest form, they take care of the distribution channels and marketing of the game. This includes things as taking care of magazine ads, reserving shelf space at the shops, getting distributors to assist them. Maybe even locally duplicating the game. Supporting the translation of the game etc. etc.
The publisher is the responsible party for taking care that the game gets from the developer to the customer.
In it's most used form however, the publishers do the above and the following: As most developing companies are unable to financially take care of the development of the game (which costs a lot these days), they 'give' the developer the money. In return they get the game and only a small percentage of the sales price then reaches the developer. Afterall the publisher needs to earn the money back also.
Publishers normally also take care of the beta testing in those cases.
I'm sure Lar can tell many tales of his experiences with the <img src="/ubbthreads/images/graemlins/div.gif" alt="" /> publisher <img src="/ubbthreads/images/graemlins/evilgrin1.gif" alt="" />
