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> It requires sharing derived code for free.

It requires you share the code with your users/the people you distributed derived works to for no additional cost. You can still charge money for the software, but you can't charge an additional fee for access to the code. You also give them the right to share it how they seem fit, so they could share it (the code, not necessarily trademarked things like names or artwork/assets) for free, share derived software including the code for a free or a fee, or not share any derived work at all.

You can read more here: https://www.gnu.org/licenses/gpl-faq.html