Displacement mapping utilizes a 2D texture map in order to generate 3D surface relief (Figure 1). As opposed to Bump and Normal mapping, Displacement mapping provides the illusion of depth and it displaces the actual geometric position of points over the textured surface. There are two types of displacement nodes available in Houdini, Displacement and Vertex Displacement.
Figure 1: Accessing the displacement nodes in an Octane VOP node