WordPress Software falls under the GPL that is General Public User License focusing on Open Source App/Software Development tools.
Here are the freedoms under the GPL:
- Freedom to run the program for any purpose.
- Freedom to study how the program works and to change it, so it performs computing as you wish.
- Freedom to redistribute copies, so you can help your neighbor.
- Freedom to distribute copies of your modified versions, giving the community a chance to benefit from your changes.
Read More about GPL here: