How is a copyright different from a trademark?

Copyright law protects the expression of ideas (such as a book, movie, song, etc.). Trademark law, on the other hand, protects words, slogans, logos, etc. which are distinctive and serve to distinguish products in the marketplace and identify their source. While the two are generally unrelated, there are instances where trademarks and copyrights can be used in conjunction with each other. For example, when a company publishes an advertisement, a trademark may protect the brand and logo appearing in the ad while copyright law would protect the creative aspects of the text and design of the ad.