Click on Grid Element
Each grid element is an actual representation of the product. It contains product image and a link to the actual product page, so when you click on any element on the grid you will be redirected to the actual product page.
Create on Backend
Each grid banner is created on backend from your selected products. Once you have it created you can drop in on your website pages using a website editor, as any other building block.
Once you change the products on backend all grid banners that were previously dropped on website will change accordingly, no need of manual re-saving.