Chronicles is the Book of Israel’s Heritage. The focus is on the spiritual heritage of Israel’s Levitical priesthood and Davidic throne. Samuel & Kings gave the history of Israel from Judges to Captivity, and Chronicles mirrors that time period, coming from a spiritual view.
1st & 2nd Chronicles (like Samuel & Kings) were originally one Book. The Hebrew title Dibrey Hayyamiym means “words (accounts) of the days.” The Greek (Septuagint) title, Paraleipomenon, means “of things omitted.” This is rather misnamed, as Chronicles does much more than provide omitted material as a supplement to Samuel & Kings. The English title comes from Jerome’s Latin Vulgate, which titled this Book Chronicorum Liber.
The traditional author of Chronicles is Ezra the priest/scribe. The conclusion to 2nd Chronicles (36:22,23) is virtually identical with the introduction to Ezra (1:1-3). Others choose to leave the author anonymous, and call him the Chronicler.