Typically you use experimental and control groups in an experiment. a control group is like the default, and the experimental is the one you actually experiment with.
for example if i run an experiment on the effects of food dye on a leaf stem, i’ll have my control group (the ones without food dye) to compare to the experimental group (the ones with food dye)
the control group is a way for scientists to see how an experiment truly affected or altered the subject
