The planet traces out an ellipse as it travels round the Sun, which is at one focus of the ellipse (Kepler's 1st. law). The planet moves faster when it is closer to the Sun, and slower when it is farther away. In fact, the area it sweeps out over equal time intervals is constant. (Kepler's 2nd. law).
The orbit shown here is quite eccentric. Most planetary orbits in our solar system are not very eccentric at all, but rather very nearly circular.