I'll pitch in with my own intuition; the easiest way to understand it is to view it as a call stack. Using this example function:

  function RecFunc(n, max) {
    let result; // intialize the return variable
    if (n < max) {
      result = RecFunc(n + 1, max) // the recursion
    } else {
      result = n; // the exit condition
    }
    return result;
  }
  RecFunc(0, 3);

When you call the function, we descend down the stack until it hits the exit condition. Notice that `result` is undefined in the upper levels of the stack; when `n` is equal to `max`, the function is finally able to assign a value to `result` and exit:

  | RecFunc
  v   n: 0, max: 3, result: undefined
  |   RecFunc
  v     n: 1, max: 3, result: undefined
  |     RecFunc
  v       n: 2, max: 3, result: undefined
  |       RecFunc
  v         n: 3, max: 3, result: 3

Now that the exit condition has been met, we go back up the stack, returning the result at each step:

  ^ RecFunc
  |   n: 0, max: 3, result: 3
  ^   RecFunc
  |     n: 1, max: 3, result: 3
  ^     RecFunc
  |       n: 2, max: 3, result: 3
  ^       RecFunc
  |         n: 3, max: 3, result: 3

Notice how the call stack resembles stepping through a for-loop:

  var result = 0;
  for (var i=0; i++; i<=3) {
    result += 1;
  }

If you really want to see a mind-blowing example of recursion, step through an implementation of the `compose`[0] function some time. :)

[0] https://github.com/reduxjs/redux/blob/master/src/compose.js