Columns are part of the row and they hold content elements inside them. Each row contains at least one column by default.
Hover your mouse over the Column area and click on Edit Column button to display column settings menu.
Within settings, you can control a width of your columns individually. Also, it is possible to set column width to different screen sizes – Extra Large, Medium, Small, and Extra Small.
You can select columns width depending on the percentage ratio of the full-width of the row. Those settings allows to create various types page structures.
Tip. In order to display more than column, you should select the needed Grid presets from the Row Settings and after, set column width.
In the image below, the Row is divided into 3 columns and set 100% default width to the first column.