allows you to select the blocks to be refined.

specifies the amount of refinement or coarsening to apply to the selected blocking. A Level value greater than 1 will result in finer mesh, while a Level value less than 1 will result in coarsening of the pre-mesh. Use fractional notation such as 1/2 or 1/3, for values less than 1.

If All is selected, the blocks will be refined in every dimension. If Selected is chosen, you can enter the dimension (edge) that specifies the direction in which to modify the block. The value 0 corresponds to the X or I direction, 1 corresponds to the Y or J direction and 2 corresponds to the Z or K direction.