Generic marks are words, symbols, etc. that describe an entire category of products or services rather than identifying a particular source of a product or service. Milk, if used as a trademark for milk, is an example. It identifies a product, not the source of it. Trademark rights cannot be claimed in generic terms for a product or service. Permitting people to claim rights in a generic term would give them monopolies on those products or services. A person with an exclusive right to use the word “milk” to sell milk would have an unfair advantage over other milk sellers. Generic terms for a product or service are never distinctive enough to be claimed as trademarks.