Definition
Logistics is the practice of getting people, supplies, and information to the place they are needed, at the time they are needed, in the condition required to act. In Sun Tzu's framing it is the silent precondition of every campaign: an army that cannot eat, move, or replace its losses cannot fight, no matter how brave or clever it is.
The term is military in origin but the principle is universal. Any organization in motion — a company shipping product, a kitchen running service, a research team chasing a deadline — succeeds or fails on the same arithmetic of throughput, distance, and consumption.
Why it matters
How it works
Sun Tzu observes that moving a thousand chariots a thousand li bankrupts the state before the first engagement. Wagons must be guarded, drovers fed, horses replaced; the further the line of supply, the more soldiers must be detached to protect it. This is why he counsels living off the enemy's land where possible — each measure of captured grain is worth twenty of one's own once transit losses are counted.
In modern terms the same calculus drives just-in-time manufacturing, forward warehousing, and the choice between owning capacity and renting it. A business that cannot move inventory, cash, or people to the point of demand at acceptable cost is in the same position as Sun Tzu's overextended general — it can win individual contests and still lose the war by attrition.
Good logistics is invisible when it works and catastrophic when it fails. The discipline rewards patience, redundancy, and a clear-eyed reading of the actual consumption rate, not the planned one.