What is the difference between an independent variable (IV) and a dependent variable (DV)?

In an experiment, the IV is a variable that is changed to see how it affects something else, whereas the DV is a variable that is being measured/observed. The DV is assumed to be affected by the IV, hence the term ‘dependent’ (its value depends on the state of the IV). For example, if an experimenter wanted to find out whether time spent studying improves exam results, the IV would be time spent studying and the DV would be exam results. TIP: If it helps, remember that ‘the IV is something I change’ and the ‘DV depends on the IV.’