What does 1 Chronicles 2:4 mean?

Tamar, Judah's daughter-in-law, had two sons for him: Perez and Zerah. Judah had five sons in total. 1 Chronicles 2:4 - Modern Text Bible

(This verse highlights Tamar's unusual role in Judah's family line, showing how Perez and Zerah were born through her, not through a typical marriage.)