Answer:
The independent variable doesn't rely on anything to change; it is independent
The dependent variable relies on the independent variable; what happens to it depends on the independent variable
Think of independent and dependent variables like cause and effect: the independent variable is the cause, while the dependent variable is the effect. For example; in an experiment, you manipulate the independent variable and measure the outcome in the dependent variable.
I hope that wasn't to confusing!
I hope this helps! (✿◕‿◕✿)