Authors

An author is anyone who contributes original expression in a work. Initial copyright ownership vests with authors or their employers.

Identify Copyrightable Components
A first step in determining ownership of a work involves identifying the copyrightable components in a work and the authors for each of those contributions.

Authors for copyright purposes are only those individuals who create the copyrightable expression. Authors in a web page or other multimedia project are the individuals who wrote the text, took the photographs, created the artwork, or wrote or performed the music. In a work such as a web page, you may have many copyrightable elements and many authors.

Creative contributions such as defining the scope of a program's functional attributes or underlying concepts, while important, are not works of authorship.

Example:  People who are not defined as authors in Copyright law 

More Than One Author
When many people contribute to a work, special issues arise. The work may be a joint work, in which case all joint authors would jointly own the work. The work may be a compilation or derivative work where existing works are combined in new ways or modified to form a new work, in which case ownership may need to be clarified through licenses or agreements.

Whether a work is a joint work, a compilation, or a derivative work is often determined by the intentions and expectations of those involved.