Natural rights are also known as?

They're also called inherent rights, basic freedoms, or natural law. If you're religious (I'm not) you may also call them God-given freedoms or rights.

The idea that men were born with natural rights was the most important belief of the enlightenment period. john Locke really liked the idea of natural rights, if you want to know more you should google him. Although...... a lot of the enlightenment thinkers believed in similar theories, so that may help you too :)