Define layout

Any component you add to a page becomes a child component of the page. Likewise, if you group component in a container-type component (for example, a Box component), the container-type is referred to as a parent and the components that it contains are referred to as child-components.

A child-component can be either self-directed or parent-directed.

A self-directed child-component can be positioned anywhere inside or outside the parent but its position is always relative to the parent.

A position of a parent-directed child-component is defined by its parent. The parent-directed layout model is powered by by the browser's built-in flexbox mechanism.