White space is the area between design elements. It is also the space within individual design elements, including the space between typography glyphs (readable characters). Despite its name, white space does not need to be white. It can be any color, texture, pattern, or even a background image.
Hierarchy is a visual design principle which designers use to show the importance of each page/screen's contents by manipulating characteristics such assize, color, contrast, repetition, and typography.