The situation is further complicated by the very nature of intellectual property. Written works, software, and chip designs aren't the kinds of things that can be placed in a locked box for safekeeping by the rightful owner. If a book or a piece of software is copied and distributed without the permission of the owner, much of the value of ownership is lost. In the United States, the basic principles of ownership of intellectual property are codified in the laws of copyrights and patents. Copyright law provides a way for authors to control the use of their original works for a specified period of time.
Patent law gives an inventor a monopoly on the use of new inventions for a specified period of time.
Both bodies of law deal with the competing claims of ownership between employees and employers. A copyright is a legal mechanism that gives the creator of the work the right to control how the work is used. A work of authorship can be a written text, a song, a film, a dance, or even a piece of software. None of these works are copyrightable however unless they are original creations of the author and are fixed in a tangible medium of expression. For example, Joe doesn't get a copyright on the song that he made up to sing in the shower every morning until he writes it down, or makes a recording of it, or otherwise fixes it in a form that could be read or heard by someone else.