Answer:
Independent Variable: The thing in an experiment which is changed.
Dependent Variable: The thing in an experiment which is affected by the change. (In other words, it's affected by the independent variable.)
Control Variable: The other factors of the experiment that remain unchanged.
For example, say you want to do an experiment about the effects of water on plant height. So, the independent variable, or the thing that is changed would be the amount of water, and the dependent variable would be the plant height, as the plant height is directly affected by the independent variable. Lastly, for this to be a fair experiment, there must be control variables. For example, all of the plants should be put in a room with equal temperature, they should get the same amount of sunlight, etc.
I hope this answers your question- feel free to ask me if you need any more help.