According to the author of Chronicles, this verse shows the family tree and important leaders of a tribe in Israel, which helps us understand who they were and how they relate to other stories in the Bible. It's like a way of telling us who was in charge and who their parents were.
1 Chronicles 2:10: And Ram begat Amminadab; and Amminadab begat Nahshon, prince of the children of Judah;
1 Chronicles 2:10 states that Ram begat Amminadab, but 1 Samuel 16:10 does not mention Ram in the genealogy or family line associated with Amminadab.
1 Samuel 16:10: Again, Jesse made seven of his sons to pass before Samuel. And Samuel said unto Jesse, The LORD hath not chosen these.