  In this paper we consider Contact graphs of Paths on a Grid (CPG graphs),
i.e. graphs for which there exists a family of interiorly disjoint paths on a
grid in one-to-one correspondence with their vertex set such that two vertices
are adjacent if and only if the corresponding paths touch at a grid-point. Our
class generalizes the well studied class of VCPG graphs (see [1]). We examine
CPG graphs from a structural point of view which leads to constant upper bounds
on the clique number and the chromatic number. Moreover, we investigate the
recognition and 3-colorability problems for $B_0$-CPG, a subclass of CPG. We
further show that CPG graphs are not necessarily planar and not all planar
graphs are CPG.
