Super Armor

Overview

Super Armor (along with the nearly-identical Autoguard) is a mechanic that lets a character shrug off successful hits from their opponent. Unlike "invincibility frames," where a character simply ignores an attack, hitting an Armored character generally has some effect on them, including damage and/or stunning them very briefly.
 
Autoguard is not to be confused with Automatic Blocking (Auto Block), an "easy mode" player-assistance mechanic that automatically causes the character to enter a blocking stance if an attack is incoming.
 

Super Armor/Hyper Armor vs. Autoguard

Super Armor (generally used in Capcom games) and Autoguard (most commonly seen in SNK games) essentially serve the same purpose. However, there are a few key differences between the two.
 
With Super Armor, a character generally takes full damage from any attack that hits them. (Street Fighter IV converts this damage into "gray," recoverable health.) However, with Autoguard, the character only takes chip damage, as they would if they regularly blocked the attack.
 
Additionally, Autoguard can be triggered infinitely, so long as a character is in a state that contains "autoguard frames." This can result in situations where characters stay in a single frame for a long amount of time, only to strike their opponent when the latter's attack is finished. On the other hand, Super Armor generally has a set number of times per move that it activates, after which the character is vulnerable to hitstun. For example, in Street Fighter IV, a Focus Attack (which has a single point of Armor) can be interrupted by two-hit attacks. Hyper Armor, a state which is very sparingly used, has infinite Armor points.
 

Examples of Super Armor in fighting games

Super Armor examples:

• Focus Attack - Street Fighter IV
• The Hulk - At all times in some games, Standing Heavy in Marvel vs. Capcom 3
• Sentinel - At all times in Marvel vs. Capcom 2, Crouching Medium in Marvel vs. Capcom 3
  

Hyper Armor examples:

• Hsien-Ko - Rimoukon hyper / Dark Force
  
• Colossus - Super Armor hyper
  

Autoguard examples:

• Kyo - Aragami/Dokugami punches
• Ralf Jones - Galactica Phantom (at certain points)
• Clark Steel - Light Argentine Backbreaker in The King of Fighters XIII