Authorship & Interaction
Copyright is basically granting exclusive rights to publish and sell literary or musical or artistic work
Copyleft is basically allowing use, distribution and modificationon the condition that any others that distribute the work should have the same beliefs.
Copyleft and copyright are basically same in functionality where both protect the right to distribute, modify and sell the documents. The two simplest examples would be Microsoft (Copyright) and Linux (Copyleft).
Microsoft products are always needed to be purchased which makes them copyrighted whereas Linux is an example of copyleft as users do not need to purchase the license to use it as it is distributed as a freeware.
Creative Commons is another example of Copyleft. What creative commons is, is a place on the web where people can publish their own works, such as artistic, musical or literary, and at the same time they can get materials by others by downloading it. In simplest words, its where everyone can share.
Deptford TV and Girltalk are licensed under the Creative Commons as well