Visible Grid makes the grid visible. Spacing defines the distance between grid markers. Enter a number and then choose pixels, inches, or centimeters from the Units pop-up menu. Color specifies the color of grid markers. The default color is light blue.
Display specifies that the grid displays as lines or dots.
Snapping turns snapping on and off. Snap Every specifies a snapping unit. Every box and choose pixels, inches, or centimeters from the Units pop-up menu. The default value is 5 pixels. To make layers snap to the grid, the grid and snap pixel units must be the same.