What does Genesis 36:18 mean?

Oholibamah’s sons—Jeush, Jalam, and Korah—were also leaders. These were the chiefs from Esau’s wife Oholibamah, the daughter of Anah. Genesis 36:18 - Modern Text Bible

(Oholibamah’s sons are listed as clan leaders, rounding out the main branches of Esau’s family.)