Copyrights fall in the category of authorship. A copyright applies to an original embodiment, but it does not have to be novel or unique in a patent sense. Copyright protection prevents other from copying it. A copyright comes into existence immediately at the time you put the work in writing or other tangible form. You can defend it by registering it with the Library of Congress.
Copyrights can protect a book, computer software, videotape, musical score, work of art, etc.
A trademark is a name to identify a product or service with its source. It lasts as long as the trademark continues to be used. You obtain registration from the U.S. Patent and Trademark Office, provided the mark is not a generic or merely descriptive name for the product or service. A trade secret can cover any special, secret information used in business. Often it is information that gives the possessor a competitive edge.