1. Copyleft is free software license requiring copyright authors to permit some of their work to be reproduced

2. The most well-known free-software license that uses strong copyleft is the GNU General Public License.

3. Activation helps verify that your copy of Windows is genuine and hasn’t been used on more devices than the Microsoft Software License Terms allow

4. Activation helps verify that your copy of Windows is genuine and hasn’t been used on more devices than the Microsoft Software License Terms allow

5. A free-software license is a notice that grants the recipient of a piece of software extensive rights to modify and redistribute that software.