Armor is a form of physical protection applied to ships or structures, or worn by individuals.
Klingon uniforms typically include body armor.
Some 24th century Starfleet and Borg vessels were equipped with ablative hull armor. (DS9: "Past Tense, Part I", VOY: "Drone")
By the early 25th century Starfleet possessed ablative generators which could surround a vessel in extremely resilient retractable armor. (VOY: "Endgame")