Around 200 BCE Apollonius of Perga proved that the circle, ellipse, parabola and hyperbola are not four separate curves — they are one cone sliced at four angles.
Tilt the plane and the eccentricity e climbs. A flat cut gives a circle (e = 0). Tilt until the plane runs parallel to the cone's own side and e hits exactly 1 — the ellipse's far focus has flown to infinity and the curve can never close again. That is the parabola, the razor's edge.
Tilt past it and the plane grabs the second cone as well: two open branches, a hyperbola, e > 1. The two gold dots are the foci; the dashed line is the directrix. Every point obeys the same law — distance to focus is e times distance to the directrix.
Kepler used this ladder to show planets ride ellipses and some comets ride parabolas — the same geometry, one turn of the dial apart.
Something in the simulation stopped unexpectedly — the lesson continues without it. Nothing you did was wrong; you can move on.