Wide Site Layout

Appearance > Customize > Layout > Container > Site Styles > Wide Site Layout.

Your entire site is consist of Main Body which includes content, header, footer & sidebar and the container which only includes the site content & sidebar. In wide site layout the main body goes with the edge to edge of the browser whereas the content & sidebar is managed by the container width.

Container Width – You can manage the container width of content & sidebar by scrolling the slider. The Minimum container width is 768 px and Maximum container width is 1920 px.