Node

With the DOT specification, a node will be created any time it is references. So if you create a bunch of edges to nodes, that will create those nodes on the graph.

You use the node command for two reasons. To specify attributes or to place a node in a specific subgraph.

Node attributes

Here is an example of specifying attributes for a node.

graph g {
    node start @{shape='house'}
    edge start,middle,end
    node end @{shape='invhouse'}
}

You can specify multiple nodes at once just like you can edges.

graph g {
    node one,three @{shape='rectangle'}
    edge one,two,three,four
}