A greedy algorithm uses small steps to formulate its solution. In each step, a decision is made to optimize the solution at that step. A greedy algorithm tells use that there is some rule we can use to make small decisions that will ultimately lead us to an optimal solution. Sometimes, greedy algorithms produce solutions that are close to optimal, but not quite optimal. A greedy algorithm works by staying ahead of the optimal solution at each step. There is also the “exchange argument” that says a possible solution can be turned into the greedy algorithm solution without altering its optimality.