CC-BY-SA, GPL, Copyleft, what?
Ok, those licenses do look terribly complicated, but the good news is, they were introduced to make things simpler.
Creative Commons
The general concept is explained here.
This video explains the license aspects better than we ever could:
Let’s have a look at BY, SA, NC and ND.
Creative Commons
“Hey world, I want you to use and spread my work!”
Attribution
“If you use my stuff, mention my name and what you changed.”
Share Alike
“Go ahead, remix, transform, build upon my work, but share your result under the same license.”
Non Commercial
“Do what you want with it, just don’t sell it.”
No Derivatives
“Pass it around, but don’t change it. No remixes and funny stuff please.”
Short Explanations
CC-BY
Creative Commons license: Attribution
Give credit, indicate changes and share your work under the same license and you are good to go!
CC-BY-SA
Creative Commons license: Attribution, ShareAlike.
Give credit, indicate changes and share your work under the same license and you are good to go!
Public Domain
This means, that the work is not protected by the copyright law.
No restrictions, but be careful, the laws are different in every country.
CC0
Like Public Domain but better. Less trouble with international laws and also it’s possible to use this license, while you are still alive :).
CC-BY-ND
This is also a Creative Commons license: Attribution, No Derivatives.
By using this license, if you want other people to remix, transform, or build upon you work, don’t use it.
CC-BY-NC
Creative Commons license: Attribution, Non Commercial.
A popular license, but authors have to realize that by using this license, their work can not be used for Wikipedia and other projects which allow commercial use.
Consider using CC-BY-SA to allowing your work to travel further but make sure your efforts remain accessible for the public.
CC-BY-NC-ND
Creative Commons license: Attribution, Non Commercial, No Derivatives.
(See above)
Mixed
Careful, this site uses different licenses. Make sure to check them, before using the content.
Unsure
It’s not quite clear what license is used. If you find out, tell us!
By the way: If you’re in doubt, it’s always best to ask the authors.
Software
This site uses (free/open source) licenses from the software world.
Most of them are quite similar to the Creative Commons licenses but they have different names and details.
Read up on Software licensed:
A Short Guide To Open-Source And Similar Licenses
Learn about a specific license:
https://tldrlegal.com/