The OODA loop is the reactive process that happens in an attack.
Air Force Col. John Boyd conceived & promoted it related to dogfights in airplanes.
Most every high level firearms school teaches it.
It stands for:
OBSERVE
ORIENT
DECIDE
ACT
First you:
OBSERVE the threat... confirm its identity whether friend or foe, distance, direction, etc.
Then you ORIENT toward it... to better evaluate its intent, speed, proximity,
Then you DECIDE what your reaction should be, fight, flight, etc.
Then you ACT ...quickly & aggressively.
Example: When a person w/ a knife comes at you, if you step a couple steps to the side very quickly, then the attacker has to react to what you did.
So your getting back ahead in the power curve & making them react to you.
That reactionary gap hopefully gives you the time to draw your weapon & direct fire in self defense.
Nice easy and it makes sense. Thank you for clarifying it for me.