Copyright
Is this Important? Lets find out.
What is Copyright?
Copyright, is the exclusive legal right, given to an originator to print, publish, perform, film, or record literary, artistic, or musical material, and to authorize others to do the same.
Copyright Licenses
Next, is Software Licenses. Written code is copyrighted: you own what you write. beyond a few lines, code does become valuable, and distributing it with a license is important. Software licenses cover the use of programming code. If you’re using a third-party library or elements from an open-source project, your usage must respect the relevant license. For example, MIT license.
Lastly, The GNU Public License. The GNU Public License is basically that we should be free to use, change, share and share changes to free software. No matter how the software is distributed, it remains free. This concept is called copyleft.
These Licenses are used for things like Wikipedia, Flickr and other things where a Copyright Licenses is necessary. Usually, Creative Commons.