Effectiveness

Achieving the planned goal at all costs, regardless of what must be done to accomplish it.

Example: A builder needs to erect a wall with 5 rows of blocks. He starts but drops 10 blocks, breaking them, and uses extra cement, taking 5 days to complete it. However, he finishes the wall. This builder is effective because he completed the wall at all costs, regardless of waste or time taken.

Efficiency

Achieving the planned goal using fewer materials, less effort, or in less time.

Example: The same builder erects the same 5-row wall but without breaking any blocks or wasting cement, and he finishes in 2 days. This builder is efficient because he completed the same work with fewer materials and in less time.