The reflow can be imagined via water. As water fit itself according to the container it is poured into. It becomes the cup when poured in cup, if poured in a glass it become glass. Similarly the content displayed on various devices need to fit and reflow the content based on the device size. For example, by using media queries the page can be authored to reflow the content based on the device dimensions. The reflow of content is also known as responsive web design (RWD). Reflow computes the layout of page. And it recomputes the position and dimension of the element.