Think of the IV and the DV as a television with bunny ears as its antenna.

IV = the bunny ears, you can change the bunny ears around- meaning the IV in an experiment is something that can be controlled/changed.
DV= The actual picture given from the bunny ears, the DV cannot be changed, meaning that the DV in the experiment is a result..
For example:
Students who study while listening to classical music tend to get higher study scores for psychology than those who don't.
IV= Music that is being played etc.[Things that can be changed]
DV= Result of the students. [Result]
EV= How loud the music is played... What artist they listen to etc. [EV are factors that can change the experiments DV]
Just a revision if you're not 100% sure on what an IV/DV/EV is.