radiusX and radiusY ?

I took the code below from this question: Instantiate prefabs in a circle or elipsoid - Unity Answers

var numPoints = 20;
var centrePos = Vector3(0,0,32);
for (var pointNum = 0; pointNum < numPoints; pointNum++)
    // "i" now represents the progress around the circle from 0-1
    // we multiply by 1.0 to ensure we get a fraction as a result.
    var i = (pointNum * 1.0) / numPoints;
    // get the angle for this step (in radians, not degrees)
    var angle = i * Mathf.PI * 2;
    // the X & Y position for this angle are calculated using Sin & Cos
    var x = Mathf.Sin(angle) * radiusX;
    var y = Mathf.Cos(angle) * radiusY;
    var pos = Vector3(x, y, 0) + centrePos;
    // no need to assign the instance to a variable unless you're using it afterwards:
    Instantiate (beadPrefab, pos, Quaternion.identity);

However, I don’t understand what radiusX and radiusY represent. If someone could clear it up for me I would appreciate it.

radiusX and radiusY are the radius of the “circle” in each of those axis. If they are equal then you will get a circle, if they are not, you will get an ellipse