This yellow div is absolutely positioned at left: 50px and top: 500px in the page's DEFAULT positioning context. Please note that the BLUE div and the GREEN div are NOT POSITIONED, and they are AFTER this yellow div in the HTML code.
This blue div is NOT POSITIONED. But it has MOVED UP to replace the YELLOW div's original place in the page (where the YELLOW div WOULD HAVE BEEN it it had not been absolutely positioned).
This green div is also NOT POSITIONED But it has MOVED UP to replace the BLUE div's original place in the page because the BLUE div has moved up. Also note that this div has width:800px; and height:300px; properties.
This pink div is NOT POSITIONED, but is contained by the GREEN div. It is after the green div's text. It has a width:300px; property.
This grey div is in its default placement by the browser.