colo-phon (noun used in publishing): A description of a publication.
The Colophon is still very much in use today, although it has received a bit of an update. The Colophon no longer exists on the last page of a publication, but more commonly on page 3 (the page directly behind the front page of a magazine) or page 5 - certainly in the first 5-7 pages of a publication.
In many countries (especially if they adher to the ISBN or ISSN standards of publication classification and serial numbering), the colophon is actually mandatory by law in all newspapers and magazines. Nearly all over the world, however, it is at the very least a tradition.
A Colophon details such information as who edited the publication, who its chief contributors are, who published it, and how to contact the publication. It will often have information about how to get in touch with the marketing department of a given publication, who its owners are, and who printed it. Some magazines list all of their contributors, while others list only the editors and most prominent contributors.
Certain publications may have a very brief history of the publication ("X was founded in 1780 in London..."), an introduction to its staff, a mission statement, or - in the cases of magazines who expect to stir up trouble, the complaints procedure, should you find the magazine to have published something out of order.
Some Colophons may also include technical details, such as the type of paper stock that was used, what type of inks, which typefaces. Some even go so far as to describe in detail which type of hardware and software was used when making the publication.