The working grid allows you to stipulate a ‘grid size’ to work with inside the live editor window.
This grid can be absolutely any sizes you wish and objects will ‘snap’ to the grid for the respective sizes.
You can use 0 to 65535, although typical values used are:
0, 2, 4, 8, 16, 32, 64
The grid information is saved inside your project so when you next re-open the project to resume working on it, the grid information is already loaded with it.
You can change the grid X/Y values at any time inside your project.