What does 2 Kings 2:1 mean?

Ahaziah died, just like God said through Elijah. Since he had no son, his brother Joram became king after him, during Jehoram's reign in Judah. 2 Kings 2:1 - Modern Text Bible

(God's word comes true. With no heir, the throne passes to Joram, and the narrative notes the overlap with Judah's king.)