The physical form that a copyrighted work may take.
U.S copyright law requires that a creative work be fixed in a “tangible medium” before it qualifies for copyright, in contrast with the law of some other countries, which confer copyright at the moment of conception.
The tangibility requirement has led to some problems with protection for types of works that are not normally “fixed”, such as dance, stand-up comedy, live musical performances, and more. It has also been the subject of much discussion with respect to computers, computer displays and computer memory, in terms of when a program or a program’s output is “fixed” or not. Some of these issues have been addressed with targeted legislation.