The purpose of copyright law is to encourage creative work by granting a temporary monopoly in an author's original creations. This monopoly takes the form of six rights in areas where the author retains exclusive control. These rights are:
(1) the right of reproduction (i.e., copying),
(2) the right to create derivative works,
(3) the right to distribution,
(4) the right to performance,
(5) the right to display, and
(6) the digital transmission performance right.
The law of copyright protects the first two rights in both private and public contexts, whereas an author can only restrict the last four rights in the public sphere. Claims of infringement must show that the defendant exercised one of these rights. For example, if I create unauthorized videotape copies of Star Trek II: The Wrath of Khan and distribute them to strangers on the street, then I have infringed both the copyright holder's rights of reproduction and distribution. If I merely re-enact The Wrath of Khan for my family in my home, then I have not infringed on the copyright. Names, ideas and facts are not protected by copyright.
Trademark law, in contrast, is designed to protect consumers from confusion as to the source of goods (as well as to protect the trademark owner's market). To this end, the law gives the owner of a registered trademark the right to use the mark in commerce without confusion. If someone introduces a trademark into the market that is likely to cause confusion, then the newer mark infringes on the older one. The laws of trademark infringement and dilution protect against this likelihood of confusion. Trademark protects names, images and short phrases.
Infringement protects against confusion about the origin of goods. The plaintiff in an infringement suit must show that defendant's use of the mark is likely to cause such a confusion. For instance, if I were an unscrupulous manufacturer, I might attempt to capitalize on the fame of Star Trek by creating a line of 'Spock Activewear.' If consumers could reasonably believe that my activewear was produced or endorsed by the owners of the Spock trademark, then I would be liable for infringement.
The law of trademark dilution protects against confusion concerning the character of a registered trademark. Suppose I created a semi-automatic assault rifle and marketed it as 'The Lt. Uhura 5000.' Even if consumers could not reasonably believe that the Star Trek trademark holders produced this firearm, the trademark holders could claim that my use of their mark harmed the family-oriented character of their mark. I would be liable for dilution.
