On the System Architecture Diagram a board's layout is defined by its board type. Each board type includes a number of
board features, such as board i/o devices, with associated
board feature types. A type is a generic description that gives technical details about a board or board feature.
Many
boards can be linked to one board type, but each board will have the same layout. In the same way board i/o devices using a common interface have one board i/o device type.