An experimental group is the group in an experiment that receives the variable being tested. One variable is tested at a time. The experimental group is compared to a control group, which does not receive the test variable. In this way, experimental groups are used to find answers in an experiment.
The difference between a control group and an experimental group is that the independent variable is changed for the experimental group, but is held constant in the control group.
In this way we came to know the result of the experiment by calculating the difference between them.