It is a right which exists in intellectual property and allows the author not to get his work transformed, copied, distributed and broadcasted freely. To perform any of these four operations you need to ask for the permission of the author and he may give them to you.
The symbol © indicates that a work is licensed under Copyright license.
Nowadays is the most used license, and is the opposite of the Copyleft license.
In case no license is specified in a work, Copyright is applied by default.
Derechos de autor (http://wikis.fdi.ucm.es/ELP/Derechos_de_autor)