Edgy with container section
Content is still within the container but if you apply the Bg modifier to the section that backgrounds should stretch from edge to edge.
Content goes always from edge to edge.
Careful with Paragraphs components, though. They have their content always in container on edgy pages.
Container section (with padding)
Classic container with a padding from each side.
Container section (without padding)
Classic container but without a padding from each side. This is the concept of NSW. You can't see the difference now but if you inspect sections, you will.