The SDM data model is the interface that
tells the SDM engine how to get the data to be displayed. The SDM
data model is an abstract description of a set of nodes and links
between nodes. Nodes and links have a user-defined type (also
called the “tag”), and a set of named properties.
JViews Diagrammer provides prebuilt data
models, and you can implement the data model interface to connect
your data.