Charles Ellicott Commentary 1 Chronicles 18:14-17

"And David reigned over all Israel; and he executed justice and righteousness unto all his people. And Joab the son of Zeruiah was over the host; and Jehoshaphat the son of Ahilud was recorder; and Zadok the son of Ahitub, and Abimelech the son of Abiathar, were priests; and Shavsha was scribe; and Benaiah the son of Jehoiada was over the Cherethites and the Pelethites; and the sons of David were chief about the king." — 1 Chronicles 18:14-17 (ASV)

David’s internal administration and high officers of state.