Super Armor is a condition that prevents a character from being knocked back or launched, allowing them to attack while taking hits. Certain skills grant this condition during their animations (particularly during 'charging' stages) and it is also gained from some buffs - most notably Iron Skin. All Bosses and Sub Bosses start out with a certain amount of Super Armor which is indicated by the yellow bar beneath their life meter.
Different attacks deplete part of a character or enemy's Super Armor and some are virtually guaranteed to break it with a single hit. Breaking any entity's Super Armor by any means grants a specific score bonus and staggers it, interrupting its current action. Bosses will furthermore be stunned when their Super Armor is broken.