Dependent variable depends upon independent variable.
For instance rent depends upon square feet of an apartment bulding. In this example rent is dependent variable which depends upon square feet which is an independent variable.
Dependent variable is also denoted as “y” variable. Independent variable is denoted as “x” variable.
When you plot the data on x-y axis, then dependent (y) variable is shown on the vertical (y) axis, and the independent variable is shown on the horizontal (x) axis.