When grid display is on, a grid appears when you zoom into the image.

The grid that is displayed is determined by the Grid Snap Distance:

When the Grid Snap Distance is set to 0 or 0.0625, the grid shows individual pixels.

When the Grid Snap Distance is set to greater than 0.0625, the grid reflects the Grid Snap Distance.

The smaller the Grid Snap Distance, the more you have to zoom in before you can see the grid.

If you decrease the Grid Snap Distance when a grid is displayed, the grid may disappear until you zoom in more.

To turn grid display on or off, do either of the following:

Press Shift+I.

Select View Menu > View Grid.