when you place a source of signal at a focal point of an ellipse, the signal will be reflected to the other focal point position
When you place a source of rays as a signal at the focal point of a hyperbola, the ray will be reflected directly away from the other focal point
When you place a source of rays as a signal at one of the parabola focus, the ray will be reflected in lines that are parallel to the axis of the parabola.