This section contains options for basic page style on all pages such as page layout, content wrapper text, page background, etc. Settings can be found under Appearance > Customize > Page Canvas & Wrapper.
There are 2 options of Page Layout: Full width and Boxed. Full width page layout will display your page fully as browser screen. On the other hand, Boxed page layout will display your page in a centered box.
Page background color
This will change the page canvas background color. The default is white.
Content wrapper width
Content wrapper is where contents on each section will be contained. Every section (like header, content, footer) has a content wrapper.
Narrow content wrapper width
In addition to the global content wrapper, there’s also Narrow content wrapper which is the wrapper that is used when you active Narrow content layout.