What is the Page Builder?
The Page Builder is a what-you-see-is-what-you-get tool to generate dynamic page layouts. Once enabled you can build pages that are simply not possible using a standard content editor.
The Page Builder works on the premise of rows, columns, and elements.
The row is the first building block of any Page Builder Page. Inside a row there are columns. And inside each column you may place elements (for example, a header, content, a list, images, etc).