2 Samuel 3:4 Meaning

2And unto David were sons born in Hebron: and his firstborn was Amnon, of Ahinoam the Jezreelitess;

3And his second, Chileab, of Abigail the wife of Nabal the Carmelite; and the third, Absalom the son of Maacah the daughter of Talmai king of Geshur;

4And the fourth, Adonijah the son of Haggith; and the fifth, Shephatiah the son of Abital;

5And the sixth, Ithream, by Eglah David's wife. These were born to David in Hebron.

6And it came to pass, while there was war between the house of Saul and the house of David, that Abner made himself strong for the house of Saul.