Copyright applies automatically to any original work (must be created by the author rather than copied) that has a minimal degree of creativity.  It must also be "fixed in [a] tangible medium, of expression" meaning that it must in some sense be recorded and perceivable, such as on paper, in a computer file, or on a DVD.

There are eight categories of works protected under copyright law:

• Literary works
• Musical works, including any accompanying words
• Dramatic works, including any accompanying music
• Pantomimes and choreographic works
• Pictorial, graphic, and sculptural works
• Motion pictures and other audiovisual works
• Sound recordings, which are works that result from the fixation of a series of musical, spoken, or other sounds 
• Architectural works

These categories should be viewed broadly and not as a definitive list. For example, computer programs can be registered as literary works, while maps can be registered as pictorial or graphical works.

Some things cannot be copyrighted: 

• Facts or ideas
• Titles, names, short phrases, or slogans
• Procedures, methods, systems or processes
• Works of the United States government
• Works that have passed into the public domain