The grid is a great function to make use of if you need precise precision and pixel perfect alignment throughout all of your banner elements. The best practice to use the grid is to use it along with the "Snap to..." function, which allows the elements to snap to the grid.
How to activate it
1. In the top-menu in the banner builder, click on View then find Grid. Toggle between the different predefined grid sizes or define a grid size of your liking.
2. After a Grid is activated, click on View again unless it's open already and then find Snap. In the Snap list, find Snap to Grid and select it to be active.
3. The elements on the canvas will now snap to the grids when moving them.