Region elements define how a rectangular portiion of your web pages looks
and behaves. It can also defines the default content for the region but this
can be overriden in layouts that contain this region.
Regions have the following features:
They can render an opening and closing tag around the content of the region.
This tag can have attributes defined including the css class name.
or more instance of the region.
They can establish a data binding context that determines how requets for
data are resolved for the descendents inside the region. For example if you
have a component that renders an address and you put this component inside
a region, the region can determine whether the address data will be the
delivery address or billing address.
They can be bound to a list of objects and repeat the content of the region
for each object in the list.