FR schemes are similar to nodal DG schemes, which are arguably the most popular type of unstructured high-order method (at least in the field of computational aerodynamics). Like nodal DG schemes, FR schemes utilise a high-order (nodal) polynomial basis to approximate the solution within each element of the computational domain, and like nodal DG schemes, FR schemes do not explicitly enforce inter-element solution continuity. However, unlike nodal DG schemes, FR methods are based solely on the governing system in a differential form. A description of the FR approach in 1D is presented below. For further information see the original paper of Huynh  [2].
