1. An intervening variable, lies between the independent variable and the dependent variable chain of cause and effect They describe the process by which an independent variable affects a dependent variable. Treatment/Control: Researchers must identify and measure intervening variables to understand the mechanisms by which independent variables influence dependent variables Statistical techniques such as path analysis and structural equation modeling can be used to analyze relationships between variables and identify intervening variables

2. Moderating variables affect the strength or direction of the relationship between the independent variable and the dependent variable These indicate under what conditions or for whom the relationship is strong or weak.

Treatment/Control: Researchers should evaluate potential moderating variables during the study design stage Statistical techniques such as moderation analysis are useful for examining how relationships between variables change based on the level of the moderating variable Including these variables in the analysis as control variables may also help reduce potential effects

I would just add a couple of details to what George Rudi Hartono Pasaribu has said. First, intervening variables are also often referred as mediating variables. Second, moderating variables involve interaction effects between the independent and dependent variable.