Answer:
The independent variable is the factor that doesn't rely / change based on another variable. Usually there is an independent, dependent, and constant variable. The dependent variable's "results" and values rely on the independent value.
For example if tomatos were to be grown the independent variable is the type of light the tomato plant is grown under. The dependent variable would be the rate of the growth of the tomato plant. (It relies on the type of light, the independent variable)