In this talk we deal with fractional differential equations, with dependence on a Caputo fractional derivative. The goal is to show, based on concrete examples and experimental data from several experiments, that fractional differential equations may model more efficiently certain problems than ordinary differential equations [1]. [1] R. Almeida, N.R.O. Bastos and M.T.T. Monteiro,  Modelling some real phenomena by fractional differential equations. Math. Meth. Appl. Sci. (39) No 16, 4846-4855 (2016)