Copyrights protect original works of authorship, including:
Computer Programs
Music
Art
Books
Movies
Architecture
Photographs
Once a work has been created, the creator owns the copyright and can stop others from making copies of the work as created. The copyright owner may also register the work with the Library of Congress and receive a Certificate of Registration which will allow the owner to use the Federal Courts to enforce the copyright. A copyright may not stop others from imitation, only from copying. The distinction between imitation and copying sometimes can be very hard to determine.