How did Jean-Jacques Rousseau distinguish natural inequality from social inequality?

In his Discourse on the Origin of Inequality, Jean-Jacques Rousseau distinguishes between two primary forms of inequality:1

• Natural (or physical) inequality: This form arises from inherent differences in human beings, such as variations in physical strength, intelligence, and other natural attributes.1
• Social (or artificial) inequality: This form is established and authorized by the conventions that govern societies. It stems from human institutions, such as the development of property, law, and government, which create disparities in wealth, status, and power.21

Rousseau argues that while natural inequality is a product of nature, social inequality is a consequence of the long process by which humans departed from their original state of nature and innocence. He posits that as people formed societies and began to compare their abilities and achievements, they developed destructive passions like jealousy and pride, ultimately leading to the institutionalization of inequality through the creation of civil society and the protection of property.21