The Grid options box has the following options.
Grid: Activating this check box causes a grid to be displayed over the chart on the screen. This is useful to position icons accurately and neatly within the chart.
The grid is a working aid only. It does not appear on the printed chart and is not stored with the chart in the project library.
Fine, Medium, Coarse: Click on one of these radio buttons to choose grid size.
Snap: When this check box is activated, all icons are positioned on the nearest grid point when created or moved, even if the grid is not displayed. Connection points can be created at any position but can only be moved to a grid point.