What is General Public License
A GPL is a type of license that allows others to freely utilize, replicate, change and give out software as long as the work created based on the original software is distributed under the same license as the original. This type of licensing is called copyleft licensing, in contrast to the copyright licensing which does not allow others to freely use the original work.
Copyleft licenses are to be distinguished from permissive licenses. Permissive licenses, like GPL licenses, authorize the use, modification, and sharing of the original work. However, permissive licenses do not require the new work based on the original to be distributed under the same license. They only necessitate the acknowledgment of the original authors of the work.