Copyright protection exists from the time the work is created in fixed form. The copyright in the work of authorship immediately becomes the property of the author who created the work. Only the author or those deriving their rights through the author can rightfully claim copyright.
In the case of works made for hire, the employer and not the employee is considered to be the author. Section 101 of the copyright law defines a “work made for hire” as:
If the parties expressly agree in a written instrument signed by them that the work shall be considered a work made for hire.
The authors of a joint work are co-owners of the copyright in the work, unless there is an agreement to the contrary.
Copyright in each separate contribution to a periodical or other collective work is distinct from copyright in the collective work as a whole and vests initially with the author of the contribution.
Source: The information on this web page is based on the Copyright Office.