The paper reviews some applications of the well-established analytical and domain discretisation methods (finite difference method-FDM, finite element method-FEM) in the modelling of the magnetohydrodynamics (MHD) phenomena for the fusion-related research and quantum structures for use in nanodevices. Hence, Grad-Shafranov Equation (GSE) for the plasma equilibrium has been implemented for certain simple excitation forms, and the results obtained for the rectangular plasma have been presented. Furthermore, the stationary Schrödinger equation is solved analytically and numerically via FDM and FEM, respectively.