What does Matthew 1:9 mean?

Matthew's listing of the genealogical line of Jesus has followed the flow of fathers and sons from Abraham through David and now into the kings of Israel who came from Solomon. Perhaps to keep the list manageable, Matthew is not including every link in the chain, skipping some generations. This was a common practice with genealogies of the day. It is still true, of course, to say that Joram fathered Uzziah, as Matthew wrote in the previous verse, even if Uzziah came several generations after Joram. The point is to show a line of descent, not to include every possible detail.

The list continues here with more kings, also listed in 1 Chronicles 3:10–14. Uzziah—also known as Azariah—fathered Jotham, who fathered Ahaz, who fathered Hezekiah.