What is a trademark?
A trademark is a brand name used by a merchant in connection with a product or service. Although a mark which is associated with a service, rather than with a product, is technically known as a “service mark,” the rules, regulations and standards are identical for service marks as for trademarks.
The focus of trademark law is on the idea of source identification. Thus, you can protect any word, name, slogan or symbol which you use in connection with a product or service if that word, name, slogan or symbol is used to indicate that you are the source of the product or service (assuming, of course, that it also meets the other trademark requirements). For example, Pepsi has trademark rights in the mark PEPSI-COLA, because the public understands that a soda which has PEPSI-COLA on its bottle comes from Pepsi. Similarly, The New York Times has trademark rights in the slogan ALL THE NEWS THAT’S FIT TO PRINT because the public recognizes that advertisements using this slogan refer to The New York Times.
If you own rights in a trademark you can, among other things, prevent someone else from using something similar in connection with their products or services if there is likely to be confusion.
Unlike patents, which are only governed by federal law, trademarks are governed by both federal law and state law.