Splines has a lot of usefulness in games, such as being the base to build scenery, like train tracks, roads, wires and so on. As well as create walkers such as cars, pedestrians, enemies among others. A spline is composed of a set of beziers, regardless of their order, quadratic, cubic or above. But it is usually made with the cubic order, having 2 tangents per point, except for the first and last points that only have one.