Public Domain, Copyright, Copyleft, Creative Commons!!

If something is in the Public Domain it means that it is free for use for anyone. Usually these are works from old dead white men or others whose intellectual property rights have expired or forfeited.

Copyright is a set of exclusive rights granted to the author or creator of an original work.  Copyright does not protect ideas, only their expression. Copyright owners have the exclusive statutory right to exercise control over copying and other exploitation of the works for a specific period of time, after which the work is said to enter the public domain. Uses covered under limitations and exceptions to copyright, such as fair use, do not require permission from the copyright owner. All other uses require permission and copyright owners can license or permanently transfer or assign their exclusive rights to others.

Copyleft is just a play on the word copyright.  Copyleft allows us the right to distribute copies and modified versions of a work.

Creative Commons is an extension of Copyright that gives you the ability to dictate how others may exercise your copyright rights. You can allow them to copy your work, make derivative works, and distribute it. There are 6 different types of Creative Common license types: Attribution, Attribution Share Alike, Attribution No Derivatives, Attribution Non-Commercial, Attribution Non-Commercial Share Alike, and Attribution Non-Commercial No Derivatives.