The UI Split block is designed to split the content into two parts. One reason to use this block is to create content that can be seen side by side on a wider screen, but then it will stack on smaller screens such as a tablet. Then in phone mobile mode, it will stack again. Another reason to use this block is to create a sidebar for your content page or pages. An example would be to have links to a group of pages in a sidebar and show those on all pages. On smaller screens, the sidebar will stack.

One special feature of this block is you can specify if you want the side / extra content on the left or right when wide or on the top or bottom when stacked. This gives extra control as to how the content will look / work on different screen sizes.

The UI Grid block allows you to split your content into sections that will stack on top of each other on a tablet, but be wide on a larger screen. Columns will be the same size as each other and will automatically resize and the number of column change automatically based on the screen size. This makes the job of building nice looking, responsive content much easier. There is a minimum size option to allow you to better control the size of the content before it stacks.

The UI Cards block provides another nice way to break up your content. It works just like the columns, as it automatically sizes and the number of cards in each row changes for different screen sizes. It also has the minimum width option to help control the size before stacking on top of each other.