1. What is the difference between an independent and dependent variable?

The independent variable is the variable that is controlled by the researcher and represents the cause of the outcome while the dependent variable is the variable that is being measured.
Think of it this way: independent variable is essentially the cause and the dependent variable is the effect.

Independent variable is the figment in a test that is unchangeable, eg, sometimes age. the dependant variable is the variable that is being measured in a test. eg, mass