El free or open source software may be under different licenses for use, the fact that a software is classified as free does not automatically make it free software, for this reason it is advisable to know the types of license that are handled in this type of Software to better understand how it works. The first of all is to clarify three basic concepts
License. The license attributed to a is the intellectual contract that is subject to copyright
Patent. They are the legal rights acquired by the creator of an intellectual work.
Copyright. They are the laws that define the rights of the creator of a work.
Types of licenses applied to software
Many times it is attributed to FOSS which is also open source and although this is generally the case, it is not always true, therefore, it is convenient to know the terms that frame both definitions in order to be able to classify the Correctly.
Free software It is one that allows the study and modification of the program for free distribution and the benefit of users.
Open source software It focuses on the practicalities of the software, which is the main difference with the FOSS that totally takes precedence over the freedoms of the individual.
An example of FOSS which is also from open source it would be his own Linux kernel that meets both requirements.
Now that we know the definitions of the main licenses applied to the FOSS we are going to specify the requirements that must be included to be admitted as Licenses GNU / Linux.
First of all, they must be approved by Open Source Initiative and have GPL designation.
Basic concepts in GNU / Linux licenses
LPG: Copyleft certain versions as long as they are under the GPL license and are free.
BDS: It makes it possible for other versions to have other licenses of different types BSD or GPL
mpl: It applies double licenses to the executables and the source code, forcing the code modifications to be delivered to its creator, licensing only the binaries.
Licenses are a difficult topic to explain, due to their complexity, but if you wanted to complicate the matter a little more, you have succeeded. What a mess you've made in a moment. And that you have not entered into the matter, practically.
Sorry I can't help, I don't have time to explain. Of course, if someone is interested in knowing what the matter of licenses and free or open source software is like, please keep looking. It is not as described here. Not at all.