What does "OODA Loop" mean?

OODA Loop:

The OODA Loop comes from mid-20th century military parlance; it was a discovery of Colonel John Boyd, a US military strategist. It stands for the decision-making process of "Observe, Orient, Decide, Act" that happens repeatedly and very quickly in combat situations--and for that matter, whenever life presents challenges. It applies to marketing in that one can work to knowingly influence the OODA loop of another person concerning a product or service purchase, by working on any of those four pieces of the loop.

 Tactical Response: OODA Loop

 Wiki: OODA