A profile system for finishing or defining a tile covering provided over a base includes at least one elongate profile that has a fastening arm and a profile section adjoining the latter which has a defining arm extending transversely, in particular at right angles, to the fastening arm and two side arms extending transversely, in particular at right angles to the free ends of the defining arm and arranged lying opposite one another, at least one illuminant that in the correct state is disposed in the receiving space defined by the substantially U-shaped profile section, and at least one elongate diffusion disc cover that can be secured to the profile.