In the top of the strongest trademarks (along with arbitrary) a fanciful mark is essentially a coined or made-up word that never existed before. These marks are generally the easiest to register and the hardest to market. Classic examples of fanciful marks are Exxon®, Kodak®, Oreo®, Xerox®. These coined words are completely invented for the sole purpose of functioning as a trademark. As such, fanciful marks are considered the strongest type of trademark, but will likely take much effort and many dollars in advertising to make the connection between the mark to the source of product or service in the eyes of consumers.
Also in the top tier, an arbitrary mark is a common word, or combination of words, used in a way that is completely different than its dictionary meaning. In other words, the literal meaning of the word or combination or words has nothing to do with the product or service. These marks are relatively easy to register and relatively hard to market. A classic example is Apple® for computers. The actual meaning of Apple is a round, edible fruit from a tree. The meaning of the word has nothing to do with computers. But, Apple has been so successful in marketing itself, that it is now associated with computers.
A suggestive trademark is suggestive of a product or service, but does not describe the product or service. In other words, the product or service given by the mark is indirect or vague. The mark does not explicitly describe what the underlying goods or services are, the mark hints at it. A classic example is the mark Coppertone®. The Coppertone trademark requires a leap of imagination and necessitates a little bit of education to explain to consumers what the product is. Suggestive marks are probably the most popular trademarks as they strike a compromise between legal strength and marketing/advertising value and expense – they are a bit easier to register and a bit harder to market.
A descriptive mark describes some quality, characteristic, ingredient or function of the product or service. In other words, a descriptive mark is one that says exactly what the product or service is. Little is left to the imagination for a consumer to determine what is being marketed or advertised. Other descriptive marks can be geographic, laudatory or personal surname words. All of these are considered weak marks and are very difficult to register. Moreover, if a mark is held to be merely descriptive of the product or service, it is not federally registrable, which means that any business or entrepreneur can use the mark.
In the lowest tier and not entitled to any trademark protection at all are generic marks. A generic mark is the common descriptive name for the good or service that it is used to identify. Thus, a generic mark cannot be a trademark because it cannot identify the goods or services coming from one source, from the same goods or services from another source. Examples include APPLES for selling apples, or SKATEBOARD for your line of skateboards.