A straight-line embedding of a graph is an embedding in Euclidean space whose edges are straight line segments that meet only at common endpoints. In the plane, such a representation is a planar straight-line embedding.
A straight-line drawing retains the straightness condition without requiring intersections to occur only at common endpoints. Although geometric and computational sources sometimes call such a drawing an embedding, the topological term straight-line embedding applies only when the edges otherwise remain disjoint.
