Albert Barnes Commentary 1 Samuel 30:14

"We made a raid upon the South of the Cherethites, and upon that which belongeth to Judah, and upon the South of Caleb; and we burned Ziklag with fire." — 1 Samuel 30:14 (ASV)

The Cherethites - This term is used here as synonymous with the Philistines (1 Samuel 30:16).

In David’s reign, the bodyguard commanded by Benaiah consisted of Cherethites and Pelethites (who may have been Philistines) and a select corps of six hundred men from Gath, commanded by Ittai the Gittite. This evidence suggests that the Cherethites and Philistines were two kindred and associated tribes, similar to the Angles and Saxons, who took possession of the seacoast of Palestine.

The Philistines, being the more powerful, gave their name to the country and the nation in general, though the name of the Cherethites was not entirely lost. Many also connect the name Cherethite with the island of Crete.