The dependent variable is the variable that is being measured in an experiment. For example, in a study looking at how tutoring impacts test scores, the dependent variable would be the participants' test scores.
In a psychology experiment, researchers are looking at how changes in the independent variable cause changes in the dependent variable. One way to help identify the dependent variable is to remember that it depends on the independent variable. When researchers make changes to the independent variable, they then measure any resulting changes to the dependent variable.
If a researcher was looking at how studying influences test scores, for example, the amount of studying would be the independent variable and the test scores would be the dependent variable. The test scores depend or vary based on the amount of studying prior to the test.