From RimWorld Wiki
The following table lists each category of armor by the type of damage it protects against. Clothing and armor will have one or more of these protective properties. Some are intrinsic to certain creatures (i.e. turtles, centipedes).
|Blunt||Armor - Blunt||The chance to prevent blunt damage like club attacks, rock falls, and explosions.|
|Piercing||Armor - Piercing||The chance to prevent piercing damage like bullets, knife stabs, and animal bites.|
|Heat||Armor - Heat||The chance to prevent temperature-related damage like burns.|
|Electric||Armor - Electric||The chance to prevent electric damage like EMP pulses.|
|Toxic||Armor - Toxic||The chance to prevent toxic damage.|