Fanciful mark has no meaning other than its meaning as a trademark. Examples include Xerox copiers, Lego bricks and Verizon phones.
Arbitrary marks have a separate meaning, but that meaning has nothing to do with their use as a trademark. Examples include Apple computers, Diesel jeans and Ivory soap.
Suggestive marks suggest a characteristic of a good or service without actually describing that characteristic.
Arbitrary, fanciful and suggestive marks receive highly similar treatment under the law. They are the strongest types of mark in that their holders do not need to prove a secondary meaning in order to protect the mark.
Because there is no reason to associate Apple with computers, outside of the popularity of computers made by Apple Computer, third parties have few legitimate reasons to use the name “Apple” on their computers.
A “descriptive” mark is one that identifies a characteristic of the article or service it marks. Examples include American Airlines (a geographic mark) and Dell Computer (a surname mark). Descriptive marks cannot be registered without proof that the mark has a secondary meaning in the eye of the consumer public.
Even if a descriptive mark has a secondary meaning, its descriptive nature makes it possible to avoid trademark infringement liability through a fair use defense. A person could, for instance, use “American Airlines” in a commercial context to refer to airlines from America, so long as they were not using the term in its trademark sense.
Generic marks like “laptop computer,” cannot receive trademark protection even if they have a secondary meaning.
The rule against generic trademarks is particularly important for holders of famous marks, because their marks may lose protection if they become common nouns or adjectives in the public eye.
Formerly-trademarked words like “aspirin” and “cellophane” have lost their protection due to genericide.
Non-verbal marks a mark need not be a word or phrase. Besides trade dress and product configuration, discussed above, trademarks can also be found in sounds (e.g. the NBC chimes), colors, fragrances, and other distinctive features of a product.
The most important criteria in determining their trademark ability is secondary meaning (whether the feature denotes origin to consumers) and whether the feature is functional. Functional features are not trademarkable: they must be protected under patent law if they are to be protected.