The Pareto Principle is also referred to as the 80/20 rule, and the concept originated from an observation made by Italian economist Vilfredo Pareto. This principle suggests that approximately 80% of effects are driven by 20% of causes. Therefore, I think one should focus on the 20% that yields 80% of the results as not everything is a priority.

Remember that results must be S.M.A.R.T (Specific, Measurable, Achievable, Relevant, and Time-Bound) and should be defined in terms of goals that can be clearly measured. If the goals are achieved, the results are accomplished, and the job is done. Efforts are actions and they specify the plan that must be executed to achieve the results.