You can quickly grasp the important difference between the two (managers and leaders) if you envision a group of producers cutting their way through the jungle with machetes. They’re the producers, the problem solvers. They’re cutting through the undergrowth, clearing it out.
The managers are behind them, sharpening their machetes, writing policy and procedure manuals, holding muscle development programs, bringing in improved technologies and setting up working schedules and compensation programs for machete wielders.
The leader is the one who climbs the tallest tree, surveys the entire situation, and yells, “Wrong jungle!”