You can read more about it here, but basically, Flexbox is a CSS3 layout model, that provides a more efficient way to lay out, align and distribute space among columns inside a container, even when their size is unknown and/or dynamic. The main idea is to give a container the ability to alter its columns’ width/height (and order) to best fill the available space, allowing responsive elements within a container to be automatically arranged, depending upon the screen size.
So in Avada 7.0, you will find new options in both the Container and the Column Elements. The main way this change affects how you can build is in Alignment and Spacing options.
In the Container Element, you will see three new options – Row Alignment, which defines how rows should be aligned vertically within the container (this will only fully work when multiple rows of content are in the container), Column Alignment, which allows you to select how you want columns to align with rows, and Column Justification, which allows you to control how the columns are aligned horizontally in the container.
And in the Column Element, you will find the new Alignment option, which defines how the column should align itself within the container (this overrides what is set on the container) and the Content Alignment option. This defines how the column content should align, and only works with full height columns.
To get a visual idea of what these options can do in practice, we will look at some examples, but first, it’s important to understand when you will see these new flex containers and columns and when you won’t.