Final answer:
Efficiency is about doing tasks correctly with the least resources to get the most output, while effectiveness is about achieving the desired results. Efficiency is measured as the ratio of useful work output to energy input. Effectiveness is not necessarily related to resource usage but to the achievement of goals.
Step-by-step explanation:
Efficiency and effectiveness are both terms related to the performance of tasks, but they have distinct meanings. Efficiency is a measure of how well resources (inputs) are used to produce desired outcomes (outputs). In this context, efficiency means doing a task correctly and getting the most output from the least amount of inputs. It is focused on maximization of productivity and minimization of waste.
For instance, an engine's efficiency can be defined as the proportion of useful energy (work) to the input energy, where Efficiency (Eff) = Wout/Ein, with Wout being the work output and Ein being the energy consumed.
On the other hand, effectiveness is about doing the right tasks and achieving desired results. It's about the end result and not necessarily about the resources used to get there. Hence, a task can be effective if it achieves its goals, even if the process wasn't the most efficient.
In summary, efficiency is related to 'doing things right,' while effectiveness is about 'doing the right things.'