US Trademark Law/Types of protected mark
Trademark law protects marks. Marks can be words, names, symbols or devices. They come in several classes:
Strictly speaking, a trademark is a mark that distinguishes one person's goods from others'. In practice, the word "trademark" is often used to refer to any class of mark that is protected under trademark law.
A service mark is similar to a trademark, except that it is used to distinguish one person's services from others'. Service marks are registrable in the same manner as trademarks and are denoted by the ® symbol once they are registered on the Principal or Supplemental Registers. If they are not registered, they often carry an SM symbol.
A trade name is a mark used to identify a business, as opposed to a good or service. The Lanham Act does not allow trade names to be registered unless they also function as trademarks or service marks by identifying the source of a good or service. However, many states allow trade names to be registered and protected under state law.
A certification mark is a mark used to certify a good in some way, regardless of its specific source. Seals of approval (e.g. the Good Housekeeping Seal of Approval) and marks of origin (e.g. Roquefort cheese) are examples of certification marks. A certification mark is held by an organization and is protected under trademark law so long as the holder establishes a standard for awarding the mark and polices that standard effectively.
A collective mark is a mark held by a group for the use of its members. Examples include union stamps and franchise marks. Collective marks are treated like regular trademarks and service marks under the Lanham Act.
Trade dress and product configuration
Trade dress refers to the distinctive packaging of a product. One example of trade dress is the decor of a restaurant chain. Trade dress is protected if it is inherently distinctive.
Product configuration refers to the distinctive design and shape of a product. The best-known example is the glass Coca-Cola bottle. A product configuration must have secondary meaning to be protected, regardless of whether it is inherently distinctive or not. Secondary meaning means that the appearance of the product should indicate its source to a consumer.
Both trade dress and product configuration can be registered as trademarks, but they are more often protected without registration as a "false designation of origin" under 15 U.S.C. § 1125(a). They pose special problems in trademark law because of their non-verbal nature. Words are easy to protect: more abstract designs are not.