Ok, so i got all confused, whats the difference between a dependent and independent variable?

Question

so... which is the one that never changes?

Answer 1

Say you are heating something over time. Time x-axis, is the independent variable. It is independent of any other variable because it has a constant rate no matter how temperature changes. Temperature, y-axis, is dependent upon time and intensity of heat applied to the flask of substance. Say, with increase in time, the substance heats up.

Answer 2

Both of them change hence the term variable, however the independent variable changes under your control where the dependent variable changes according to how you control the independent variable.

Answer 3

The independent variable is the one that you control.  You pick the values for the independent variable.  The value of the dependent variable, well, depends on your choice of the independent variable.

======= Follow up =======

Neither will not change.  The values of the independent and dependent variables both change value during the course of an experiment.  You're thinking of keeping a variable fixed (or constant) when there are multiple variables.

In an experiment we want to manipulate only two variable sat a time. One will be the one that the experimenter controls and the other will depend on how the independent variable is manipulated.