By default, each page starts out with 3 columns that you can add blocks to build on top of. You have the ability to add up to 5 columns for content. The more columns you have, the more content you can add to a page.
To change the columns on a site:
- Scroll to the bottom of the Grid to the tools
- In the middle, you'll have the option to select 3, 4, or 5 columns
- The changes will immediately be reflected on the Grid editor