There are two main types of variables:
* Independent variable: This is the factor that the experimenter intentionally changes or manipulates. It is the "cause" in a cause-and-effect relationship.
* Dependent variable: This is the factor that is being measured or observed in response to the changes in the independent variable. It is the "effect" in a cause-and-effect relationship.
For example, in an experiment testing the effect of fertilizer on plant growth, the independent variable is the amount of fertilizer applied, and the dependent variable is the height of the plant.
