Your product and collection pages are a crucial part of your store. The product grid tab has global settings that affect both of those page types.
Most notably, you can change the aspect ratio for your product grid to make the blocks wider, taller, or square (1:1)
You can set the image to stretch across the block or to render itself in full inside of it. The latter can result in extra white spaces while the former could cut parts off. The most important thing here is to set the proper aspect ratio.
Another great option tucked away under this tab is the 'products per row'. This is split into two different settings, one for mobile and one for desktop.
