A trademark is a word, phrase, symbol, and/or design that identifies and distinguishes the source of the goods or services of one party from those of others. Where a trademark serves as a source identifier services, you may see it referred to as a service mark. For example, MCDONALDS is used as a trademark for both goods and services. The MCDONALDS service mark covers the brick and mortar retail stores and food services that McDonalds offers to the public. Fun fact: McDonalds once sued a dentist for using the term McDental as a service mark for providing dental services.
When you speak with a trademark lawyer, you may hear them refer to the “registrability” of your trademark. This term refers to the fact that not all words, logos, slogans, etc., can be registered as a federal trademark with the United States Patent and Trademark Office.
The strength of a trademark depends on what trademark category the mark falls under. There are five categories of trademarks: generic trademarks, descriptive trademarks, suggestive trademarks, arbitrary trademarks, and fanciful trademarks.