"A trademark is a marketing tool used to support a company’s claim that its products or services are authentic or distinctive compared with similar products or services from competitors. TRIPS defines a trademark as “any sign, or any combination of signs, capable of distinguishing the goods or services of one undertaking from those of other undertakings”. It usually consists of a distinctive design, word, or series of words placed on the product label and perhaps displayed in advertisements. For example, Coca Cola is a trademark that can only be used on goods manufactured by the Coca Cola Company. Registered trademarks are usually renewable indefinitely, though in most jurisdictions this is subject to continued use. The trademark owner has the exclusive right to prevent third parties from using identical or similar marks in the sale of identical or similar goods or services where doing so is likely to cause confusion." (http://www.iprsonline.org/guide/index.htm)
"A trademark is a word, phrase, symbol, or design used to identify the source of goods or services sold, and to distinguish them from the goods or services of others. For example, the Coca-Cola mark and the design that appears on their soft drink cans identifies them as pro¬ducts of that company, distinguishing them from competitors such as Pepsi. Trademark law primarily prevents competitors from “in¬fringing” upon the trademark, i.e., using “confusingly similar” marks to identify their own goods and services. Unlike copyrights and pat¬ents, trademark rights can last indefinitely if the owner continues to use the mark. The term of a federal trademark registration lasts ten years, with ten-year renewal terms being available.
Other rights related to trademark protection include rights against trademark dilution, certain forms of cybersquatting, and various “unfair competition” claims. IP also includes recent legal innovations, such as the mask work protection available for semiconductor in¬tegrated circuit (IC) designs, the sui generis protection, similar to copyright, for boat hull designs, and the proposed sui generis right in databases, or collections of information." (http://mises.org/books/against.pdf)