The Breakpoint Container is a simple container whose purpose is to swap sub-containers based on a ‘breakpoint’ in pixels. This allows for a very simple responsive design that removes one container and replaces it with another when the breakpoint (typically viewport width) is reached. With the Breakpoint container, you can define completely different content to render for each breakpoint. This is in contrast to a container such as the column container, where the content for each breakpoint is identical but the layout of it changes according to screen size. See also Breakpoint Containers
Breakpoint Containers are ideal to use in cases where you want completely different components available between a mobile user or a desktop user, since the components in each breakpoint are completely separate instances. Thus, if you're attempting to make a responsive view, and a Flex Container isn't quite giving you the result you're looking for, a Breakpoint Container may be a better fit.