The Erased component contains linework in the section object that you do not want to see. For example, if you have a section of a multi-story building in which you want to hide the lines between each floor, you can edit the linework of the section and assign the floor lines to the Erased component. Since the Erased component is turned off by default, the floor lines do not display.
The Erased component is specific to 2D sections.
The Erased component cannot be defined by a material component.