what is the independent variable in an experiment

In an experiment, the independent variable is the variable that is manipulated, controlled, or varied to explore its effects. It is the factor that is changed in an experiment, and it is not influenced by any other variables in the study. For example, in an experiment investigating the effect of exercise on heart rate, the independent variable would be the amount of exercise performed. It is important to have only one independent variable in an experiment, as otherwise, it can be difficult to determine which variable caused the observed change.