outerFunction is the outer function, and it has a local variable outerVariable.innerFunction is the inner function that logs the outerVariable to the console.outerFunction returns innerFunction, and when we call closureFunction, which is assigned to the returned innerFunction, it still has access to the outerVariable even though outerFunction has finished executing.
This is the essence of a closure: the inner function retains access to the variables of the outer function.