Okay, so imagine you have a big book about the history of a country called Israel. In this book, there are many stories about kings who ruled over Israel. One of those stories is about two kings named Azariah and Zechariah.
Azariah was a king who ruled over Israel for a long time. He started off really great and did many good things for his people. He built up the city walls and made sure they had plenty of food and water. But, as time went on, Azariah became very proud and stubborn. He thought he could do whatever he wanted and didn't have to listen to anyone, not even to God. Because of his disobedience, God punished Azariah by giving him a terrible skin disease that he suffered from until his death.
After Azariah died, his son Zechariah became the new king. But, Zechariah was nothing like his father. He was evil and did many bad things. He didn't care about his people or even his own family. After only 6 months of being king, Zechariah was assassinated by one of his own officers, who then became king.
And that's the story of the two kings in 2 Kings 15. It's a reminder that good leaders should listen to God and care for their people, while bad leaders will suffer the consequences of their actions.