Adding Spaces and Lines
You can use the af:spacer component to incorporate some blank space in your pages between components, so that the page appears less cluttered than it would if all the components were right next to each other. You can include either or both vertical and horizontal space in a page by using the following attributes:
height: The amount of vertical space to include in the page; use with width not set to create vertical spacer, surrounded with a paragraph tag so that it appears on its own line
width: The amount of horizontal space to include between components; use with height not set to create horizontal spacer
The af:separator component creates a horizontal line on the page.