To explain results shown on a layer in the 3dview in grid format, right-click on the layer and select "Save property as grid". The outlines of areas (e.g. for a drainage area) can be saved by using the "Save property as outline".
Results can also be automatically each time a timestep is simulated. The timesteps, layers and properties for which output results shall be stored is defined in the File->Output Table component. See the Migri Help pages for more details on the usage.