A copyright is a collection of rights automatically vested to you once you have created an original work. To understand how these rights can be used or licensed, it is helpful to analogize them to a bundle of sticks, where each stick represents a separate right vested to you as the owner. These rights include the right to reproduce the work, to prepare derivative works, to distribute copies, to perform the work publicly, and to display the work publicly.
As the copyright owner, you have the authority to keep each “stick,” to transfer them individually to one or more people, or to transfer them collectively to one or more people. This can be accomplished through licensing, assigning, and other forms of transfers. The power of copyright allows you to choose the way your work is made available to the public.
For example, you may wish to grant rights in your work to a business partner only for a specific use, in a specific territory or for a specific time period, in order to maintain flexibility to license the other rights to other business partners who may be better equipped to help you monetize them. Similarly, you may wish to grant just a limited set of your rights to better allow you to understand and control how your work will be used. For instance, if you are a musician, you may wish to grant the use of your song only with respect to advertising a particular product or service in a limited jurisdiction so that it does not undermine the value of the work in other jurisdictions. If you are a filmmaker, you may wish to grant the right to sell your foreign rights to a foreign sales agent but retain the US rights to sell yourself.
Finally, copyright also gives you the power to do nothing with your creative work and retain each of the rights yourself. For more information, see Purpose and Goals of Copyright, under Copyright Basics.