MeshRange is an option for ListPlot3D, SurfaceGraphics, ListContourPlot, ListDensityPlot and related functions which specifies the range of and coordinates that correspond to the array of values given.
specifies ranges in and . Mesh lines are taken to be equally spaced.
MeshRange->Automatic takes and to be a grid of integers determined by indices in the array.
Settings for MeshRange are produced automatically by Plot3D, etc. for insertion into SurfaceGraphics etc.
MeshRange is used to determine tick values for surface, contour and density plots.