Is a factor that's effected by changes in the independent variable

the dependent variable

Explanation:

lets say you're investigating the affect sunlight has on plant growth (measured by height).

If you have two plants, you're putting one in sunlight and one in complete shade. The amount of light you're giving is independent, since the amount of light doesn't change because of how much the plant grows. But, since the plant needs light to grow, it will grow more or less depending on how much light it has