In this website, it demonstrates the scientific definition of what leverage is. In science, leverage is the ratio of change in output to the change in input. The equation to calculating leverage is =leverage x force = change. In other words, leverage multiplied by the amount of force is equal to the change. This website also discusses four MAJOR terms to know:
Change force: Effort required to prepare and make a change
leverage point: Place in structure where a solution element can be applied
low leverage point: small amount of force causes small change
high leverage point: small amount of force causes big change
In all, a great site reviewing and analyzing the definition of leverage.