A trademark can be a logo, name, symbol, or device used to differentiate a product or service of one trader (or commercial entity) from that of another-brand identity. Example: McDonalds' golden arches. Trademark protection lasts for 10 years after registration, and is renewable.
Trade secrets (covered by state rather than federal laws) include formulas, patterns, device or any compilation of data that gives a company a tangible advantage over its competitors (e.g., Coca Cola's formula for its soft drink).
A Copyright is protection granted to authors of original authorship such as literary, dramatic, musical and artistic works, and computer software, as well as performing artists in their performances, producers of phonograms in their recordings, and broadcasters in their radio and television programs. Example: The creators of your favorite music CD, movie, or computer game have a copyright on their work. Copyrights last for the life of an author plus 50 years.