Trademarks (marks) are words, phrases, designs, sounds, symbols, color combinations or any combination thereof (such as product packaging) that serves to identify the source of the goods identified with the mark. A Service Mark is the same, applied to a source of services. One mark can be used to identify a source of both goods and services. Trademarks and Service Marks are granted by both the federal government and each state government. Unlike patents and copyrights, trademarks can exist in perpetuity (notwithstanding the Rule against Perpetuities), provided the mark continues to be used in commerce or is not otherwise abandoned or misused.

While a federal trademark requires the mark to be used in interstate commerce, a state registration can be used to protect a local or regional mark from competitive use. Trade names (business names, which can include incorporations, partnerships and fictitious names) are closely associated with trademarks. While trade names perform many of the same functions of trademarks or service marks by identifying a business, they are not identical, instead serving to identify and differentiate the business entity rather than to associate a good or service with the entity. Nevertheless, a single mark can be used to perform both functions. Coca-Cola® is the company: it's also the product. I'll give Pepsi® the same courtesy, for those that favor the latter. The ® symbol means the mark is registered. A Ô symbol indicates that the word, phrase or design is being used, and claimed, as a trademark, but is not federally registered. The SM symbol performs the same function for Service Marks. While a trademark holder may sue for infringing uses of their mark, the primary focus in the grant of trademarks or service marks is to protect the public.

The likelihood that the public may be mislead or confused as to the source of a product or service by the misuse of trademarks is the linchpin of both federal and state trademark infringement law. An infringer is subject to claims for injunctive relief, damages and, in some instances, attorney's fees.