Copyright is one of three types of intellectual property law, along with patents and trademarks. Copyright gives authors and creators a limited right to control the use of their expression. Expression is how people convey their ideas, and it can include books, drawings, paintings, sculptures, photographs, music, movies, sound recordings, and computer software programs. Copyright protects only expression, not the idea or fact that is being expressed. For example, a history book will include many base facts and ideas, as well as some original ideas that the author developed on his or her own. A second author (or filmmaker, etc.) can use any of the facts and ideas contained in the book but would need permission to copy the original author's expression.

Expression must be fixed (stored) in a tangible medium before it is protected by copyright. Recording music on a cassette tape, painting on a canvas, or...